Filter
Top Products
16
CHAPTER 3 REGISTERS
3.1 F
2
MC-8FX Registers
In the F
2
MC-8FX series, there are two types of registers: dedicated registers in the CPU,
and general-purpose registers in memory.
■ F
2
MC-8FX Dedicated Registers
The dedicated register exists in the CPU as a dedicated hardware resource whose application is restricted to
the CPU architecture.
The dedicated register is composed of seven types of 16-bit registers. Some of these registers can be
operated with only the lower 8 bits.
Figure 3.1-1 shows the configuration of seven dedicated registers.
Figure 3.1-1 Configuration of Dedicated Registers
■ F
2
MC-8FX General-Purpose Registers
The general-purpose register is as follows:
• Register bank: 8-bit length: stores data
16 bits
PC
A
T
IX
EP
SP
RP CCR
PS
Initial value
0000
H
0000H
0000H
0000H
0000H
FFFDH
Program counter: indicates the location of the stored instructions
Accumulator: temporarily stores the result of operations and transfer
Temporary accumulator: performs operations with the accumulator
Index register: indicates address indexes
Extra pointer: indicates memory addresses
Stack pointer: indicates the current location of the top of the stack
Program status: stores register bank pointers, direct bank pointer
and condition codes
CCR: IL1, 0 = 11
Other flags = 0
RP : 00000
DP : 000
DP