Zilog Z8F0130 - Manual (Page 29)

eZ8
™
CPU Core
User Manual
UM012820-0810 Z8
®
Compatibility
14
Alternate Function Op Code
To accommodate the new instructions, the Op Code 1Fh refers to a new
second Op Code map. The 1Fh is prepended to an Op Code to select the
alternate functions available on the second Op Code map. The CPC,
CPCX, SRL, LDWX and PUSH (immediate) instructions use this second
Op Code map. You can employ the CPC, CPCX, SRL, LDWX and PUSH
(immediate) instructions directly when writing assembly language code.
The eZ8 CPU assembler automatically inserts the
1Fh Op Code as neces-
sary.
Moved Instructions
Some of the existing Z8 CPU instructions have been moved to new

Op Codes in the eZ8 CPU. Table 5 lists the moved instruction.
Removed Instructions
The instruction types LD r1, R2 and LD R1, r2 are removed from the Op
Code map because they are now subsets of the LD instruction (Op Code
E4h) using Escaped mode addressing. In the Z8 CPU, these instructions
used Op Codes
08h – F8h and 09h – F9h . The assembler for the eZ8 CPU
Table 5. Instructions with New Op Codes
Instruction
eZ8 CPU
Op Code (Hex)
Z8 CPU
Op Code (Hex)
SRP 01 31
DEC R1 30 00
DEC IR1 31 01
JP IRR1 C4 30
NOP 0F FF