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Summary of Contents for Z8 Encore!

Page 1: ...Z8 Microcomputer Technical Manual April 1983...

Page 2: ...c...

Page 3: ...Z8 Microcomputer Technical Manual n_...

Page 4: ...ight 1983 by Zilog Inc All rights reserved No part of this publication may be reproduced without the written permission of Zilog Inc The information in this publication is subject to change without no...

Page 5: ...1 Introduction 2 2 Address Spaces 2 3 Register File 2 3 1 Register Pointer 2 3 2 Instruction Set 2 3 3 Data Types 2 3 4 Addressing Modes 2 4 I O Operations 2 4 1 Timers 2 4 2 Interrupts 2 5 Oscillato...

Page 6: ...tion Codes D Notation and Binary Encoding 5 4 1 Assembly Language Syntax 5 4 2 Condition Codes and Flag Settings 5 5 Instruction Summary 5 6 Instruction Descriptions and Formats Chapter 6 External Int...

Page 7: ...Timing Z8681 Reset Conditions Z8682 Reset Conditions Chapter 8 Reset and Clock 8 1 Reset 8 2 Clock 8 3 Power down Operation 8 4 Test Mode 8 4 1 8 4 2 Interrupt Testing ROMless Operation Chapter 9 I O...

Page 8: ...rces 10 3 Interrupt Request Register Logic and Timing 10 4 Interrupt Initialization 10 4 1 10 4 2 10 4 3 Interrupt Priority Register Initialization Interrupt Mask Register Initialization Interrupt Req...

Page 9: ...Conditions Chapter 12 Serial I O 12 1 Introduction 12 2 Bit Rate Generation 12 3 Receiver Operation 12 4 12 5 12 3 1 Receiver Shift Register 12 3 2 Overwrites 12 3 3 Framing Errors 12 3 4 Parity Tran...

Page 10: ...Pointer Stack Operations Register Addressing Working Register Addressing Indirect Register Addressing to Register File Indirect Register Addressing to Program or Data Memory Indexed Addressing Direct...

Page 11: ...lator External Clock Interface Battery Backed Register Supply Normal and Test Mode Flow Voltage Waveform for Test Mode I O Port and Port Mode Registers Ports 0 1 and 2 Block Diagram Port 0 I O Operati...

Page 12: ...11 18 Cascaded Counter Timers Figure 11 19 Counter Timer Reset Figure 11 20 Prescaler 1 Register Reset Figure 11 21 Prescaler 0 Reset Figure 11 22 Timer Mode Register Reset Figure 12 1 Figure 12 2 Fig...

Page 13: ...Table 9 1 Table 10 1 Table 10 2 Table 12 1 Z8 Family of Products Condition Codes Control and Peripheral Register Reset Values Port 3 Line Functions Interrupt Types Sources and Vectors Interrupt Priori...

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Page 15: ...stems development both hardware and software prototyping field trials pre production and full production For prototyping and preproduc tion or where code flexibility is important the ZS603 13 Protopac...

Page 16: ...1 1 ZB Family of Products ROM Part Capacity Progr able Dedicated PCB Product Ntnber Bytes I O Pins I O Pins Footprint Conments 2K ROM Z8601 2K 32 4 ports 8 Power 40 Pin Masked ROM part used Control p...

Page 17: ...ts Ports 0 1 2 3 can be programmed as input output or additional address lines The I O ports can also be programmed to provide timing status signals interrupt inputs and serial or parallel I O with or...

Page 18: ...yte register file on board UART and two coun ter timers are provided Pin descriptions and fund ions are t he same as those for the Z8601 11 basic microcomputer Chapter 6 1 4 1 7 ROHlESS MICROCOMPUTER...

Page 19: ...perate on the data before output to the printing mechanism I alll y VV L V o Disk Disk operations are read or write with input received from either the disk or the compu ter Data is transferred to the...

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Page 21: ...nternal and external Data memory external Register file internal A maximum of 64K bytes of program memory are directly addressable In the Z8601 and Z8611 microcomputers internal program memory consist...

Page 22: ...ion and a Swap instruction Decimal Adjust is used after a binary addition or subtraction on BCD digits 2 2 Logical Shift Rotate and Load instructions oper ate on bytes in the register file Bytes in da...

Page 23: ...ntain the contents of the register file with a low power battery Architectural Overview 2 6 PROTOPACK The lB Protopack allows the user to prototype system hardware and develop software that is eventua...

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Page 25: ...241 240 127 4 2 STACK POINTER BITS 7 0 STACK POINTER BITS 15 8 REGISTER POINTER PROGRAM CONTROL FlAGS INTERRUPT MASK REGISTER INTERRUPT REOUEST REGISTER INTERRUPT PRIORITY REGISTER PORTS 0 1 MODE PORT...

Page 26: ...ter thus forming an 8 bit address Figure 3 4 illustrates this opera tion Since working registers are typically specified by short format instructions there are fewer bytes of code needed which reduces...

Page 27: ...ers PO P3 are registers The functions and applications of control and peripheral registers are described in subsequent sections of this manual Address Spaces 3 4 CPU PROGRAM MEMORY The ZS can access...

Page 28: ...AL ROM OR RAM IR05 IR05 JP IR04 IR04 JP IR03 IR03 JP IR02 IR02 JP IR01 IR01 JP IROO IROO JP NOT ADDRESSABLE Figure 3 5d Z8682 Program Memory Map When an interrupt occurs the address stored in the inte...

Page 29: ...2 bit and 16 bit addresses External data memory can be included with or sep arated from the external program memory addressing space When data memory is separated from program memory the Data Memory o...

Page 30: ...on The stack address always points to the data stored on the top of stack The Z8 stack is a return stack for Call instructions and interrupts as well as a data stack During a Call instruction the cont...

Page 31: ...bit values or memory addresses A register pair must be speci fied as an even numbered address in the range 0 2 14 Addressing modes are instruction specific Section 5 4 discusses each addressing mode a...

Page 32: ...onvention When accessing program memory or external data memory register pairs or working register pairs are used to hold the 16 bit addresses 8 BIT REGISTER FILE ADDRESS PROGRAM MEMORY REGISTER FILE...

Page 33: ...ess of the next instruction to be executed The PC prior to the add consists of the address of the instruction following the Jump Relative JR or Decrement and Jump if Nonzero DJNZ instruction JR and DJ...

Page 34: ...indicate a reg ister or memory address as the source operand the operand value used by the instruction is the value supplied in the operand field itself Because an immediate operand is part of the in...

Page 35: ...BC dst src Subtract With Carry SUB dst src Subtract Chapter 5 Instruction Set Logical Instructions Mnemonic Operands AND dst src COM dst OR dst src Instruction Logical And Complement Logical Or XOR ds...

Page 36: ...ag is set to 1 whenever the result of an arithmet ic operation generates a carry out of or a borrow into the high order bit 7 otherwise the Carry flag is cleared to O Following Rotate and Shift instru...

Page 37: ...carry out of bit 3 Overflow or a subtraction generates a borrow into bit 3 The Half carry flag is used by the Decimal Adjust DA instruction to convert the binary result of a pre vious addition or subt...

Page 38: ...ires that dst src be specified in that order The following instruction descriptions show the format of the object code produced by the assembler This binary format should be followed by users who pref...

Page 39: ...I Minus S 0100 OV Overflow V 1100 NOV No overflow V 0 0110 EQ Equal Z 1 1110 NE Not equal Z 0 1001 GE Greater than or S XOR V 0 equal 0001 LT Less than S XOR V 1 1010 GT Greater Than Z OR S XOR V O 00...

Page 40: ...127 128 SRA dst lE I DO 0 EI 9F Dl IMR 7 I SRP src 1m 31 INC dst rE RP src dst dst 1 r O F SUB dst src Note I 20 I R 20 dst dst src IR 21 SWAP dst R FO X X INCW dst RR AO IR FI dst dst IR Al TCM dst s...

Page 41: ...addition of high order operands C Set if there is a carry from the most significant bit of the result cleared otherwise Z Set if the result is zero cleared otherwise 5 Set if the result is negative c...

Page 42: ...rom the most significant bit of the result cleared otherwise Z Set if the result is zero cleared otherwise V Set if arithmetic overflow occurs that is if both operands are of the same sign and the res...

Page 43: ...corresponding bits in the two operands are both 1s otherwise a 0 bit is stored The contents of the source bit are not affected C Unaffected Z Set if the result is zero cleared otherwise V Always reset...

Page 44: ...ints to the first instruction of a procedure At the end of the procedure a R Turn instruction can be used to return to the original program flow RET pops the top of the stack back into the PC No flags...

Page 45: ...Exmnple C NOT C CCF Complement Carry Flag Cycles 6 OPC Hex EF The C flag is complemented if C 1 it is changed to C 0 and vice versa C Complemented No other flags affected Tf the C flag contains a 0 th...

Page 46: ...__ 6 BO B1 R IR Operation Flags Exmnple Note 5 12 dst 0 The destination location is cleared to O No flags affected If working register 6 contains AF the statement CLR R6 will leave the value 0 in that...

Page 47: ...bits are changed to 0 and vice versa C Unaffected Z Set if the result is zero cleared otherwise V Always reset to 0 5 Set if result bit 7 is set cleared otherwise H Unaffected D Unaffected If working...

Page 48: ...C Cleared if there is a carry from the most significant bit of the result set otherwise indicating a borrow Z Set if the result is zero cleared otherwise V Set if arithmetic overflow occurs cleared ot...

Page 49: ...Carry Instruction Before DA Hex Before DA Hex To Byte After DA 0 0 9 0 0 9 00 0 0 0 8 0 A F 06 0 ADD 0 0 9 1 0 3 06 0 ADC 0 A F 0 0 9 60 1 0 9 F 0 A F 66 1 0 A F 1 0 3 66 1 1 0 2 0 0 9 60 1 1 0 2 0 A...

Page 50: ...ed in the destination location using standard binary arithmetic 0001 0101 0010 0111 0Ul1 T11iU 3C The DA statement adjusts this result so that the correct BCD representation is obtained 0011 1100 0000...

Page 51: ...one c Unaffected Z Set if the result is zero cleared otherwise V Set if arithmetic overflow occurred cleared otherwise 5 Set if the result is negative cleared otherwise H Unaffected D Unaffected If wo...

Page 52: ...lue which is decremented by one C Unaffected Z Set if the result is zero cleared otherwise V Set if arithmetic overflow occurred cleared otherwise 5 Set if the result is negative cleared otherwise H U...

Page 53: ...is reset to O All interrupts are disabled although they remain potentially enabled i e the Global Interrupt Enable is cleared not the individual interrupt level enables No flags affected If control re...

Page 54: ...is the address of the instruction byte following the DJNZ statement When the working register counter reaches zero control falls through to the statement following DJNZ No flags affected DJNZ is typi...

Page 55: ...er 251 the Interrupt Mask Register is set 10 to 1 This allows any potentially enabled interrupts to become enabled No flaqs affected If control register 251 contains OA 00001010 that is interrupts IRQ...

Page 56: ...e incremented by one C Unaffected Z Set if the result is zero cleared otherwise V Set if arithmetic overflow occurred cleared otherwise S Set if the result is negative cleared otherwise H Unaffected 0...

Page 57: ...incremented by one C Unaffected Z Set if the result is zero cleared otherwise V Set if arithmetic overflow occurred cleared otherwise S Set if the result is negative cleared otherwise H Unaffected 0...

Page 58: ...SP 2 IMR 7 1 Cycles 16 ope Hex SF This instruction is issued at the end of an interrupt service routine It restores the Flag reqister control register 252 and the PC It also reenables any interrupts...

Page 59: ...wing the JP instruction is executed See Section 6 4 for a list of condition codes The unconditional jump simply replsces the contents of the Program Counter with the contents of the specified register...

Page 60: ...See Section 5 3 for a list of condition codes The range of the relative address is 127 128 and the original value of the PC is taken to be the address of the first instruction byte following the JR st...

Page 61: ...on Flags Example Note dst src The contents of the source are loaded into the destination source are not affected No flags affected The contents of the If working register 0 contains OB 11 decimal and...

Page 62: ...s used to load a byte constant from program memory into a working register or vice versa The address of the program memory location is specified by a working register pair The contents of the source a...

Page 63: ...king register pair and the address of the register file location is specified by a working register The contents of the source location are loaded into the destination location Both addresses are then...

Page 64: ...5 30 dst src This instruction is used to load a byte from external data memory into a working register or vice versa The address of the external data memory location is specified by a working registe...

Page 65: ...ed by a working register pair and the address of the register file location is specified by a working register The contents of the source location are loaded into the destination location Both address...

Page 66: ...NOP No Operation NlF Instruction format ope Operation flags 5 32 Cycles 6 OPC Hex FF No action is performed by this instruction It is typically used for timing delays No flags affected...

Page 67: ...results in a one bit being stored whenever either of the corresponding bits in the two operands is 1 otherwise a 0 bit is stored C Unaffected Z Set if result is zero cleared otherwise V Always reset t...

Page 68: ...oaded into the destination The SP is then incremented automatically No flags affected If the SP control registers 254 255 contains 1000 external data memory location 1000 contains 55 and working regis...

Page 69: ...nts of the SP are decremented then the contents of the source are loaded into the location addressed by the decremented SP thus adding a new element to the top of the stack No flags affected If the SP...

Page 70: ...ReF Reset Carry Flag ReF Instruction For at Cycles ope 6 Operation e 0 The e flag is reset to 0 regardless of ita previous value Flags c Reset to 0 No other flags affected 5 36 OPC Hex eF...

Page 71: ...L instruction The contents of the location addressed by the SP are popped into the PC The next statement executed is that addressed by the new contents of the PC No flags affected If the PC contains 3...

Page 72: ...rom the roost significant bit position was 1 i e bit 7 was 1 Z Set if the result is zero cleared otherwise V Set if arithmetic overflow occurred that is if the sign of the destination changed during r...

Page 73: ...t if the bit rotated from the most significant bit position was 1 i e bit 7 was 1 Z Set if the result is zero cleared otherwise V Set if arithmetic overflow occurs that is if the sign of the destinati...

Page 74: ...nificant bit position was 1 Le bit 0 was 1 Z Set if the result is zero cleared otherwise V Set if arithmetic overflow occurred that is if the sign of the destination changed during rotation cleared ot...

Page 75: ...rotated from the least significant bit position was 1 i e bit 0 was 1 Z Set if the result is zero cleared otherwise V Set if arithmetic overflow occurred that is the sign of the destination changed du...

Page 76: ...on of high order operands C Cleared if there is a carry from the most significant bit of the result set otherwise indicating a borrow Z Set if the result is 0 cleared otherwise V Set if arithmetic ove...

Page 77: ...SCf Instruction format Cycles ope 6 Operation e 1 The e flag is set to 1 regardless of its previous value flags c Set to 1 No other flags affected SCF Set Carry Flag OPC Hex DF 5 43...

Page 78: ...d and its value is also shifted into bit position 6 7 o c Set if the bit shifted from the least significant bit position was 1 i e bit 0 was 1 Z Set if the result is zero cleared otherwise V Always re...

Page 79: ...ter group The working register group starting addresses are Hex Decimal 00 0 10 16 20 32 30 48 40 64 50 80 60 96 70 112 FO 240 control and peripheral registers Values in the range 80 EO are invalid No...

Page 80: ...ignificant bit of the result set otherwise indicating a borrow Z Set if the result is zero cleared otherwise V Set if arithmetic overflow occurred that is if the operands were of opposite signs and th...

Page 81: ...are swapped C Undefined Z Set if the result is zero cleared otherwise V Undefined S Set if the result bit 7 is set cleared otherwise H Unaffected 0 Unaffected Suppose the register named BCD_nperands...

Page 82: ...checked to determine the result When the TeM operation is complete the destination location still contains its original value C Unaffected Z Set if the result is zero cleared otherwise V Always reset...

Page 83: ...ult When the TM operation is complete the destination location still contains its original value c Unaffected Z Set if the result is zero cleared otherwise V Always reset to 0 S Set if the result bit...

Page 84: ...XCLUSIVE OR operation results in a one bit being stored whenever the corresponding bits in the operands are different otherwise a 0 bit is stored c Unaffected Z Set if the result is zero cleared other...

Page 85: ...m Port 1 for each external memory transfer During a Write cycle data out is valid at the leading edge of OS During a Read cycle data in must be valid prior to the trailing edge of OS 55 can be placed...

Page 86: ...llowing access to 256 bytes of external memory In this configuration the eight lower order address bits AO A7 are multiplexed with the data DO D7 Port 0 can be programmed to provide four addi tional a...

Page 87: ...should not be immediately followed by the instructions RET or IRET because this will cause indeterminate program flow 3047 002 3047 003 External Interface ZS601 ZS611 6 5 DATA I tI1RY The two external...

Page 88: ...es that valid data is on the Port 1 ADO AD7 lines For Read operations R W High the Address Data bus is placed in a high impedance state before driving DS L6 so that the addressed device can put its da...

Page 89: ...e common resources with other bus masters This shared bus mode is under software control and is programmed by setting Port 0 1 Mode register bits D4 and D3 both to 1 Figure 6 7 Data transfers can be c...

Page 90: ...setting bit DS in the Port 0 1 Mode register to 1 Figure 6 8 Figures 6 9a and 6 9b illustrate extended memory Read and Write cycles R248 P01M Port 0 1 Mode Register F8 Write Only EXTERNAL MEMORY TlMI...

Page 91: ...cycles have the same machine timing regardless of whether memory is internal or exter nal For those instructions that require execu tion time longer then that of the overlapped fetch or instructions...

Page 92: ...STORE FETCH 1 FETCH 2 EXECUTION CYCLE II OPERAND INSTRUCTION INSTRUCTION FETCH ES ALU STORE FETCH 1 FETCH 2 EXECUTION CYCLE II INSTRUCTION INSTRUCTION FETCH 1 FETCH 2 EFFECTIVE _I HIDDEN DELAY I EXEC...

Page 93: ...N I I Figure 6 11 Instruction Cycle Timing One Byte Instructions Ml M2 Ml OR M3 r T1 1 r T3 I Tl T2 T3 T2 r T3 CLOCK PO ______ X Aa A15 X Aa A15 X Aa A15 P1 X Ao A7 s Ao A7 Ao A7 AS OS I R W FETCH 3RD...

Page 94: ...alues reset into P01M 6 10 R248 P01M Port 0 1 Mode Register F8 Write Only P04 P07 MODE OUTPUT 00 INPUT 01 A12 A15 1X EXTERNAL MEMORY TIMING NORMAL 0 EXTENDED 1 I P08oP U T 01 INPUT 1X As All STACK SEL...

Page 95: ...ta Strobe provides the timing for data movement to or from Port 1 for each memory transfer During a Write cycle data out is valid at the leading edge of 55 During a Read cycle data in must be valid pr...

Page 96: ...ammed to provide either four additional address lines A8 A11 which increases the addressable memory to 4K bytes or eight additional address lines A8 A15 which increases the addressable memory to 64K b...

Page 97: ...ter F8 Write Only P04 P01 MODEI OUTPUT 00 r POa P03 MODE L 00 OUTPUT 01 INPUT 1X As All INPUT 01 A12 A15 1X Figure 7 5 Z8681 Port 0 Memory Operation The lower nibble of Port 0 can be defined as addres...

Page 98: ...7 4 EXTERNAL STACKS The l8681 82 architecture supports stack opera tions in either the register file or data memory A stack s location is determined by bit D2 in the Port 0 1 Mode register For exampl...

Page 99: ...e of AS indicates that R W OM if used and the addresses output from Ports 0 and 1 are valid The addresses output via Port 1 remain valid only during MnT1 and typically need to be latched using AS wher...

Page 100: ...hardware reset Port 0 is configured as input port extended timing is set to accommodate slow memory access during the configuration routine DM is inactive and the stack resides in the register file Fi...

Page 101: ...d Peripheral Register Reset Values Register FO Serial I O F1 Timer Mode F2 Counter Timer F3 f1 Prescaler F4 Counter Timer a F5 TO Prescaler F6 Port 2 Mode F7 Port 3 Mode F8 Port 0 1 Mode ZB601 ZB611 F...

Page 102: ...nternal pull up combined with an external capacitor of 1 eF provides enough time to properly reset the Z8 Figure 8 2 R W Figure B 1 8 2 B 2 CLOCK The Z8 derives its timing from on board clock circuitr...

Page 103: ...eneral purpose regis ters whenever VCC is removed During normal operation V MM provides 5 V along with VCC The following sequence is necessary to preserve data Power failure must be externally detecte...

Page 104: ...ditional on board ROM is mapped into the first 64 locations of program memory Figure 8 7 shows the difference between Normal and Test modes of operation Test mode is entered by driving the RESET input...

Page 105: ...lock 80C and 80F interrupt vectors in the Z8611 point to external memory locations 1000 1003 Q1006 1008 100C and 100F These interrupt vectors allow the external program to have a 2 or 3 byte JUMP inst...

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Page 107: ...ts 9 1 2 Input and Output Registers Each bit of Ports 0 1 and 2 has an input regis ter an output register associated buffer and control logic Since there are separate input and output registers associ...

Page 108: ...UT BUFFER A A K 8 K Ecf READ_r PORT INTERNAL TIMING HANDSHAKE SELECTED HANDSHAKE WRITE LOGIC PORT 8 J y Y OUTPUT ENABLE OUTPUT REGISTER OUTPUT BUFFER figure 9 2 Ports 0 1 and 2 Block Diagra 8 y I 8 PO...

Page 109: ...or as outputs by setting both D6 and 07 to O 9 2 2 Handshake Operation When used as an I O port Port 0 can be placed under handshake control by programming the Port 3 Mode register bit 02 to 1 Figure...

Page 110: ...ut strobe Using the Port 0 1 Mode register Port 1 is con figured as an output port by setting bits 04 and 0 3 to Os or as an input port by setting 04 to 0 and 03 to 1 Figure 9 6 R248 P01M Port 0 1 Mod...

Page 111: ...drain output the data returned is the value forced on the output pin by the external system This may not be the same as the data in the output register Reading input bits of Port 2 also returns data...

Page 112: ...ister for each bit Instead all the input lines have one input regis ter and output lines have an output register Under software control the lines can be con figured as input or output special control...

Page 113: ...t 3 The special functions indicated in the table are discussed in detail in their corresponding sections in this manual Port 3 input lines P30 P33 always function as interrupt requests regardless of t...

Page 114: ...Load P01 M or P2M to configure the port for input output Load P3 to set the Output Handshake bit to a logic 1 Load P3M to select the Handshake mode for the port Once a data transfer begins the configu...

Page 115: ...us returning the in terface to its initial state Figure 9 16 zn Output Handshake l U Ports Figures 9 17 and 9 18 illustrate the strobed handshake connections 9 7 I O PORT RESET CONDITIONS A P2o P27 K...

Page 116: ...R248 P01M Port 0 1 Mode Register F8 Write Only P04 P07 MODE OUTPUT 00 J INPUT 01 A12 A15 1X EXTERNAL MEMORY TIMING NORMAL 0 EXTENDED 1 c POO P03 MODE L 00 OUTPUT 01 INPUT 1X As All STACK SELECTION o...

Page 117: ...e Only 0 01010101011101 I LoPORT 2 PULL UPS OPEN DRAIN 1 PORT 2 PULL UPS ACTIVE RESERVED o P32 INPUT P3s OUTPUT 1 P32 DAVO RDYO P3s RDYO DAVO o0 P33 INPUT P34 OUTPUT P33 INPUT P34 DM 1 1 P33 DAVlIRDY1...

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Page 119: ...ts both vectored and polled interrupt handling Details on vectored and polled interrupts can be found in Sections 10 6 and 10 7 DEC HEX IDENTIFIERS 251 INTERRUPT MASK FB IMR 250 INTERRUPT REQUEST FA I...

Page 120: ...nternal IRQ3 can be generated from an external source only if Serial In is not enabled otherwise its source is internal The ext ernal request is generated by a negative edge signal on P30 as shown in...

Page 121: ...e before an opcode fetch Figure 10 6 External requests are sampled two internal clocks earlier due to the synchronizing flip flops shown in Figures 10 3 and 10 4 At sample time the request is transfer...

Page 122: ...iority of the individual members within the three groups Bits DO 03 and 04 are encoded to define six priority orders between the three groups Bits 06 and 07 are not used R2491PR Interrupt Priority Reg...

Page 123: ...BLES IR02 1 ENABLES IR03 1 ENABLES IR04 1 ENABLES IR05 1 ENABLES INTERRUPTS Figure 10 8 Interrupt Mask Register 3047 095 3047 064 Interrupts IRQ is held in a Reset state until an EI instruc tion is ex...

Page 124: ...Cycle Tiaing Interrupt cycle timing for all Z8 devices except the Z8681 is diagrammed in Figure 10 12 Timing for the Z8681 ROMless device is different and is shown in Figure 10 13 10 6 2 Nesting of Ve...

Page 125: ...t for request If no request go to NEXT If request is there then service it SERVICE Process Request AND IRQ IIMASK_ Clear Request bit RET Return to next In this example if IRQ2 is being polled MASK wil...

Page 126: ..._ SERVICE ROUTINE L J _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ FOR STACK EXTERNAL ONLY Figure 10 12 ROM Z8 Interrupt T ing shrink parts l _ M3_ STACK PUSH_I_STACK PUSH_I_STACK PUSH I VE6 ii IGH_1 v...

Page 127: ...r timer operates in either Single Pass or Continuous mode At the end of count counting either stops or the initial value is reloaded and counting continues Under software control new values are loaded...

Page 128: ...trol bits that specify TO and T1 counting modes These bits also indicate whether the clock source for T1 is internal or external These control bits will be discussed in detail throughout this chapter...

Page 129: ...2 machine state after the operand is fetched Figure 11 7 11 3 2 Prescaler Operations During counting the programmed clock source drives the prescaler 6 bit counter The counter is counted down from the...

Page 130: ...counter timer value 1 256 It should be apparent that the prescaler and counter timer are true divide by n counters 11 4 TOUT MODES The Timer Mode register TMR F1 Figure 11 10 is used in conjunction w...

Page 131: ...h to 1 The internal clock XTAL frequency 2 is then direct y output on P36 Figure 11 12 R241 TMR Timer Mode Register F1 Read Write TIN MODES EXTERNAL CLOCK INPUT 00 GATE INPUT 01 TRIGGER INPUT 10 NON R...

Page 132: ...d disabled state of T1 IRQ2 must therefore be masked or enabled according to the needs of the application T N 1 P31 H D CLOCK IU1 i INTERNAL CLOCK 1 D j 11 5 1 External Clock Input Hode The TIN Extern...

Page 133: ...2 OSC 2 P3l 0 0 f 4 r PREO INTERNAL CLOCK TMR 05 1 EDGE 4 TRIGGER 1 TMR 05 04 11 Figure 11 17 Triggered Clock Mode TO f 4 2 f P3s TOUT TIN Figure 11 18 Cascaded Counter Ti mers PRE1 T1 P3l H PRE1 L IR...

Page 134: ...rated on every end of count 11 6 CASCADING COUNTER TIMERS For some applications it may be necessary to mea sure a time interval greater than a single coun ter timer can measure In this case TIN and TO...

Page 135: ...e Register F1 Read Write 10101010101010101 TOUT MODES I TOUT OFF 00 To OUT 01 L0 NO FUNCTION 1 LOAD To T1 OUT 10 INTERNAL CLOCK OUT 11 TIN MODES EXTERNAL CLOCK INPUT 00 GATE INPUT 01 TRIGGER INPUT 10...

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Page 137: ...are to access the serial I O as general purpose registers eliminating the need for special instructions 12 2 BIT RATE GENERATION When Port 3 Mode register bit D6 is set to 1 the serial I O is enabled...

Page 138: ...r Mode register TMR F1 bits Dl and DO both to 1 Figure 12 6 This transfers the contents of the Prescaler and Counter Timer registers to their corresponding down counters In addition counting is enable...

Page 139: ...the internal clock by two D type flip flops before being input to the Shift register and the start bit detection circuitry The ntart bit detection circuitry monitors the incoming data stream looking...

Page 140: ...ead Received Oata No Parity 12 3 4 Parity The data format supported by the receiver must have a start bit eight data bits and at least one stop bit If parity is on bit 07 of the data received will be...

Page 141: ...software to respond to IRQ4 appropriately I f polling is used the IRQ4 bit in the Interrupt Request regis ter must be reset 12 4 2 Parity The data format supported by the transmitter has a start bit e...

Page 142: ...1 I ld 1 _____ SERIAL DATA Do LSB 12 6 Figure 12 11 Serial I O Register Reset R247 P3M Port 3 Mode Register F78 Write Only 1010101010101 101 L 0 PORT 2 PULL UPS OPEN DRAIN 1 PORT 2 PULL UPS ACTIVE oP...

Page 143: ...A...

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Page 145: ...ch Appendix A Pin Descriptions and Functions cycle when the first 4K bytes of program memory are being accessed SClK System Clock output SCLK is the inter nal clock output through a buffer The clock r...

Page 146: ...POs P2s P07 P2s P27 P10 P11 P30 PORT 1 P12 P31 BYTE P13 P32 PROGRAMMABLE P14 Z8612 P33 PORT 3 1 0 OR ADo AD7 SERIAL AND PARALLEL P1s P34 1 0 CONTROL P1s P3s P17 P3s P37 Do D1 PROGRAM D2 A1 MEMORY D3 D...

Page 147: ...P16 P03 15 50 Z8812 P1s Figure A J Protopack Emulator P04 16 49 P14 GNO 17 48 P13 POs 18 47 Ph SOCKET FOR 2716 EPROM 2732 EPROM P06 19 46 P11 21 P07 20 45 P10 lACK 21 44 07 DD SYNC 22 43 06 SCLK 23 42...

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Page 151: ...CK SOURCE 1 T INTERNAL o T EXTERNAL TIMING INPUT T N MODE PRESCALER MODULO RANGE 1 64 DECIMAL 01 00 HEX R244 TO Counter Timer 0 Register F4H Read Write T INITIAL VALUE WHEN WRITTEN RANGE 1 256 DECIMAL...

Page 152: ...OUP B C B A 101 o IRQ2 IRQO B A C 110 1 IRQO IRQ2 RESERVED 111 IRQ1 IRQ4 PRIORITY GROUP C o IRQl IRQ4 1 IRQ4 IRQl R250 IRQ Interrupt Request Register FAH Read Write I I I I I I I I I RESERVED T c IRQO...

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Page 155: ...IM IRI IM 6 5 10 5 10 5 10 5 10 5 SUB SUB SUB SUB SUB fl lr R RI IR RI Ri lM IRI IM f 6 5 10 5 10 5 10 5 10 5 SBC SBC SBC SBe SBe rl lr R RI IR RI Ri lM IRI IM f 6 5 10 5 10 5 la S 10 5 OR OR OR OR O...

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Page 159: ...3 Control registers 3 3 B 1 Counter timers 1 1 1 3 1 4 2 2 11 1ff Cascaded 11 8 Continuous mode 11 1ff Enable Count bit 11 3 Load bit 11 3 Reset conditions 11 9 Index Counter Timers cont d Single Pass...

Page 160: ...terface 6 1ff 7 1ff Handshake 9 3 Read Write 7 4 9 3 Port 0 1 Mode register P01M 3 3 3 6 6 2ff 7 3ff 9 3ff Port 1 1 4 9 4 Handshake 9 4 Read Write 9 4 Port 2 9 5 Handshake 9 5 Read Write 9 5 Port 2 Mo...

Page 161: ...2 4 U UART Universal Asynchronous Receiver Transmitter 1 1 1 3 1 4 2 2 x XTAL1 XTAL2 Crystal 1 2 signals 6 2 z Zero flag Z see Flags Z8 Development Module OM 1 1 1 2 Z8 Emulator Z SCAN 8 1 1 1 2 Z8601...

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Page 163: ...ware Model and Memory Size Describe your likes dislikes concerning this document Supporting Diagrams EaseofUse _____________________________________________________________ Your Name _________________...

Page 164: ...SINESS REPLY MAIL FIRST CLASS PERMIT NO 35 CAMPBELL CA POSTAGE WILL BE PAID BY Zilog 1315 Dell Ave Campbell California 95008 ATTENTION Corporate Publications No Postage Necessary If Mailed In The Unit...

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Page 166: ...stin TX 78757 Phone 512 453 3216 Zilog Inc 1315 Dell Ave Campbell California 95008 03 3047 03 East Sales Technical Center Zilog Incorporated Corporate Place 99 South Bedford S1 Burlington MA 01803 Pho...

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