32
CHAPTER 5 CPU
5.1
Dedicated Registers
The CPU has its dedicated registers: the program counter (PC), two arithmetic registers
(A and T), three address pointers (IX, EP, and SP), and the program status (PS) register.
Each of the registers is 16 bits long. The PS register consists of the register bank
pointer (RP), direct pointer (DP), and condition code register (CCR).
■
Configuration of Dedicated Registers
The dedicated registers in the CPU are seven 16-bit registers. Accumulator (A) and temporary accumulator
(T) can also be used with only their lower eight bits in service.
Figure 5.1-1 shows the configuration of the dedicated registers.
Figure 5.1-1 Configuration of Dedicated Registers
■
Functions of Dedicated Registers
●
Program counter (PC)
The program counter is a 16-bit counter which contains the memory address of the instruction currently
executed by the CPU. The program counter is updated whenever an instruction is executed or an interrupt
or reset occurs. The initial value set immediately after a reset is the mode data read address (FFFD
H
).
●
Accumulator (A)
The accumulator is a 16-bit register for arithmetic operation. It is used for a variety of arithmetic and
transfer operations of data in memory or data in other registers such as the temporary accumulator (T). The
data in the accumulator can be handled either as word (16-bit) data or byte (8-bit) data. For byte-length
arithmetic and transfer operations, only the lower eight bits (AL) of the accumulator are used with the
upper eight bits (AH) left unchanged. The initial value set immediately after a reset is 0000
H
.
Address
FFFD
H
PC
: Program counter
Contains the address of the current instruction.
0000
H
AH
AL
: Accumulator (A)
Temporary storage register for arithmetic operation and
transfer.
0000
H
TH
TL
: Temporary accumulator (T)
Performs an operation with accumulator.
0000
H
IX
: Index register
Register containing an index address.
0000
H
EP
: Extra pointer
Pointer containing a memory address.
0000
H
SP
: Stack pointer
Contains the current stack location.
0030
H
RP
DP
CCR
: Program status
Register consisting of the register bank pointer, direct bank
pointer, and condition code register.
16 bits
PS
Summary of Contents for F2 MC-8FX Family
Page 2: ......
Page 4: ......
Page 34: ...20 CHAPTER 1 DESCRIPTION ...
Page 38: ...24 CHAPTER 2 HANDLING DEVICES ...
Page 39: ...25 CHAPTER 3 MEMORY SPACE This chapter describes memory space 3 1 Memory Space 3 2 Memory Map ...
Page 56: ...42 CHAPTER 5 CPU ...
Page 73: ...59 CHAPTER 6 CLOCK CONTROLLER ...
Page 96: ...82 CHAPTER 6 CLOCK CONTROLLER ...
Page 104: ...90 CHAPTER 7 RESET ...
Page 105: ...91 CHAPTER 8 INTERRUPTS This chapter explains the interrupts 8 1 Interrupts ...
Page 174: ...160 CHAPTER 10 TIMEBASE TIMER ...
Page 184: ...170 CHAPTER 10 TIMEBASE TIMER ...
Page 218: ...204 CHAPTER 13 WATCH PRESCALER ...
Page 257: ...243 CHAPTER 16 8 16 BIT COMPOSITE TIMER ...
Page 261: ...247 CHAPTER 16 8 16 BIT COMPOSITE TIMER ...
Page 288: ...274 CHAPTER 16 8 16 BIT COMPOSITE TIMER ...
Page 301: ...287 CHAPTER 17 16 BIT PPG TIMER ...
Page 316: ...302 CHAPTER 17 16 BIT PPG TIMER ...
Page 382: ...368 CHAPTER 21 UART SIO DEDICATED BAUD RATE GENERATOR ...
Page 390: ...376 CHAPTER 22 I2C ...
Page 395: ...381 CHAPTER 22 I2C ...
Page 399: ...385 CHAPTER 22 I2C ...
Page 430: ...416 CHAPTER 23 10 BIT A D CONVERTER ...
Page 476: ...462 CHAPTER 24 LCD CONTROLLER ...
Page 482: ...468 CHAPTER 25 LOW VOLTAGE DETECTION RESET CIRCUIT ...
Page 494: ...480 CHAPTER 26 CLOCK SUPERVISOR ...
Page 507: ...493 CHAPTER 27 REAL TIME CLOCK ...
Page 523: ...509 CHAPTER 27 REAL TIME CLOCK ...
Page 532: ...518 CHAPTER 27 REAL TIME CLOCK ...
Page 536: ...522 CHAPTER 28 256 KBIT FLASH MEMORY ...
Page 554: ...540 CHAPTER 28 256 KBIT FLASH MEMORY ...
Page 564: ...550 CHAPTER 29 EXAMPLE OF SERIAL PROGRAMMING CONNECTION ...
Page 595: ...581 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
Page 596: ...582 INDEX Index ...
Page 597: ...583 INDEX ...
Page 600: ...586 Pin Function Index ...
Page 602: ......