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MSM66591/ML66592 User's Manual
Chapter 3 CPU Architecture
3
C. Instructions for increment, decrement, and arithmetic and logic operation and com-
parison to PSW or PSWH (content of PSW or PSWH is undefined after the instruc-
tion is executed).
If an interrupt occurs, PSW is automatically saved during an interrupt transition cycle,
and automatically returns when an RTI instruction is executed.
PSW is assigned to SFR, and the content becomes 0000H at reset (when the
RES
signal is input, the BRK instruction is executed, the watchdog timer is overflown, or an
operation code trap is generated.)
A description of each PSW bit follows:
Bit 15: carry flag (CY)
A carry flag is set to "1" if:
• carry from bit 7 occurs in a byte operation
• borrow to bit 7 occurs in a byte operation
• carry from bit 15 occurs in a word operation
• borrow to bit 15 occurs in a word operation
as a result of executing an arithmetic instruction and a comparison instruction,
otherwise, it is set to "0". Carry flags can be set/reset depending on the instruction,
and can transmit/receive data for the bit specified by register. A carry flag can be
tested by a conditional branch instruction.
Bit 14: zero flag (ZF)
A zero flag is set to "1" if:
• the value is zero as a result of an arithmetic instruction execution
• the loaded content is zero when a load instruction to ACC is executed
• the target bit is zero when a bit operation instruction is executed
otherwise, it is set to "0". A zero flag can be tested by a conditional branch instruction.
Bit 13: half carry flag (HC)
A half carry flag is set to "1" if a carry or borrow from bit 3 occurs as a result of execut-
ing an arithmetic operation and comparison instruction (same for both byte and word
operations), otherwise, it is set to "0".
Bit 12: data descriptor (DD)
A data descriptor indicates the attributes of data stored in ACC, and
• If DD is "1", ACC data is valid for 16 bits
• If DD is "0", ACC data is valid for the low-order 8 bits
When DD is referred to for an arithmetic instruction and data transfer instruction
execution with ACC:
• the operation and transfer in word units are executed if DD is "1"
• the operation and transfer in byte units are executed if DD is "0"
DD is set to "1" or "0" when the data transfer instruction to ACC is executed, and also
set or reset when a dedicated set or reset instruction is executed.
This means that:
• DD is set to "1" when a word type load instruction to ACC is executed, and when an
SDD instruction is executed.
• DD is set to "0" when a byte type load instruction to ACC is executed, and when an
RDD instruction is executed.
Summary of Contents for MSM66591
Page 15: ...Contents 12...
Page 17: ......
Page 18: ...Overview Chapter 1 1...
Page 19: ......
Page 30: ...Description of Pins Chapter 2 2...
Page 31: ......
Page 44: ...CPU Architecture Chapter 3 3...
Page 45: ......
Page 101: ...3 56 MSM66591 ML66592User sManual Chapter 3 CPU Architecture...
Page 102: ...CPU Control Functions Chapter 4 4...
Page 103: ......
Page 111: ...4 8 MSM66591 ML66592User sManual Chapter 4 CPU Control Functions...
Page 112: ...Memory Control Functions Chapter 5 5...
Page 113: ......
Page 117: ...5 4 MSM66591 ML66592User sManual Chapter 5 Memory Control Functions...
Page 118: ...Port Functions Chapter 6 6...
Page 119: ......
Page 152: ...Output Pin Control Pin OE Chapter 7 7...
Page 153: ......
Page 155: ...7 2 MSM66591 ML66592User sManual Chapter 7 Output Pin Control Pin OE...
Page 156: ...Clock Generation Circuit Chapter 8 8...
Page 157: ......
Page 160: ...Time Base Counter TBC Chapter 9 9...
Page 161: ......
Page 164: ...Watchdog Timer WDT Chapter 10 10...
Page 165: ......
Page 170: ...Flexible Timer FTM Chapter 11 11 11...
Page 171: ......
Page 213: ...11 42 MSM66591 ML66592User sManual Chapter 11 Flexible Timer FTM...
Page 214: ...General Purpose 8 Bit Timer Function Chapter 12 12...
Page 215: ......
Page 223: ...12 8 MSM66591 ML66592User sManual Chapter 12 General Purpose 8 Bit Timer Function...
Page 224: ...PWM Functions Chapter 13 13...
Page 225: ......
Page 244: ...Baud Rate Generator Functions Chapter 14 14...
Page 245: ......
Page 263: ...14 18 MSM66591 ML66592User sManual Chapter 14 Baud Rate Generator Functions...
Page 264: ...Serial Port Functions Chapter 15 15...
Page 265: ......
Page 348: ...A D Converter Functions Chapter 16 16...
Page 349: ......
Page 381: ...16 32 MSM66591 ML66592User sManual Chapter 16 A D Converter Functions...
Page 382: ...Transition Detector Functions Chapter 17 17...
Page 383: ......
Page 387: ...17 4 MSM66591 ML66592User sManual Chapter 17 Transition Detector Functions...
Page 388: ...Peripheral Functions Chapter 18 18...
Page 389: ......
Page 392: ...External Interrupt Request Function Chapter 19 19...
Page 393: ......
Page 396: ...Interrupt Request Processing Function Chapter 20 20...
Page 397: ......
Page 407: ...20 10 MSM66591 ML66592User sManual Chapter 20 Interrupt Request Processing Function...
Page 408: ...Bus Port Functions Chapter 21 21...
Page 409: ......
Page 413: ...21 4 MSM66591 ML66592User sManual Chapter 21 Bus Port Functions...
Page 414: ...Expansion Port Chapter 22 22...
Page 415: ......
Page 420: ...Serial Port with FIFO SCI5 Chapter 23 23...
Page 421: ......
Page 431: ...23 10 MSM66591 ML66592User sManual Chapter 23 Serial Port with FIFO SCI5...
Page 432: ...RAM Monitor Function Chapter 24 24...
Page 433: ......
Page 441: ...24 8 MSM66591 ML66592User sManual Chapter 24 RAM Monitor Function...
Page 442: ...25 Electrical Characteristics Chapter 25...
Page 443: ......
Page 458: ...Package Dimensions Chapter 26 26...
Page 459: ......
Page 461: ...26 2 MSM66591 ML66592User sManual Chapter 26 Package Dimensions...
Page 462: ...Revision History Chapter 27 27...
Page 463: ......
Page 465: ...27 2 MSM66591 ML66592User sManual Chapter 27 Revision History...