UM012811-0904
eZ8 CPU Instruction Set Description
eZ8 CPU
User Manual
153
PUSHX
Push using Extended Addressing
PUSHX src
Operation
SP
←
SP - 1
@SP
←
src
Description
The Stack Pointer contents decrement by one. The source operand contents are loaded into
the location addressed by the decremented Stack Pointer, adding a new element to the
stack.
Flags
Attributes
Escaped Mode Addressing
Using Escaped Mode Addressing, address mode ER can specify a Working Register with
4-bit addressing.
If the high byte of the source or destination address is EEH (11101110B), a Working Reg-
ister is inferred. For example, the operand EE3H selects Working Register R3. The full 12-
bit address is given 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 desired Working Group.
C
Unaffected.
Z
Unaffected.
S
Unaffected.
V
Unaffected.
D
Unaffected.
H
Unaffected.
Mnemonic
Source
Opcode (Hex)
Operand 1
Operand 2
Operand 3
PUSHX
ER2
C8
ER2[11:4]
{ER2[3:0], 0H}
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