Zilog Z8F0130 - Manual (Page 215)

eZ8
™
CPU Core
User Manual
UM012820-0810 POPX Instruction
200
Attributes
Escaped Mode Addressing
Using Escaped Mode Addressing, address mode ER specifies 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 the Stack Pointer (control Registers FFEh and FFFh ) contains the value
D70h and Register D70h contains the value 44h , the following statement
loads the value 44h into Register 345h :
POPX 345h

Object Code: D8 34 50
After the POP operation, the Stack Pointer contains the value D71h . The
contents of Register D70h are not affected.
Mnemonic Destination
Op
Code
(Hex) Operand 1 Operand 2 Operand 3
POPX ER1 D8 ER1[11:4] {ER1[3:0],
0h} —