Zilog Z8F0130 - Manual (Page 145)

eZ8
™
CPU Core
User Manual
UM012820-0810 CPX Instruction
130
Attributes
Escaped Mode Addressing
Using Escaped Mode Addressing, address mode ER for the source or des-
tination can specify a working register with 4-bit addressing.
If the high byte of the source or destination address is EEh ( 11101110b ),
a working register is inferred. For example, the operand EE3h selects
Working Register R3. The full 12-bit address is provided by {RP[3:0],
RP[7:4], 3h} .
To access registers on Page Eh (addresses E00h to EFFh ), set the Page
Pointer, RP[3:0], to Eh and set the Working Group Pointer, RP[7:4] , to
the preferred Working Group.
Sample Usage
If Register AB3h contains 16h and Register 911h contains 20h , the fol-
lowing statement sets the C and S flags, and clears the Z and V flags:
CPX %AB3, %911

Object Code: A8 3B
If Register 26Ch contains 2Ah , the following statement sets the Z flag,
and clears the C, S, and V flags:
CPX 26Ch, #2Ah

Object Code: A9 6C 2A
Mnemonic
Destination,
Source
Op
Code
(Hex)
Operand 1 Operand 2 Operand 3
CPX ER1, ER2 A8 ER2[11:4] {ER2[3:0],
ER1[11:8]} ER1[7:0]
CPX ER1, IM A9 IM {0h,
ER1[11:8]} ER1[7:0]