eZ80
®
CPU
User Manual
UM007714-0908 CPU Instruction Set
294
RET cc
Conditional Return from Subroutine
Operation
if cc {
PC ← (SP)
}
Description
If the condition is true (1), the
RET
instruction returns program control back to the point
in the user’s application code that had reached the current subroutine via a
CALL
instruc-
tion. The return address pops from the stack and is written to the Program Counter. The
MADL control bit must be set to 1 to enable mixed-ADL mode code and interrupts. If the
MADL is reset to 0, the suffixed instructions do not operate correctly. More detailed oper-
ation is provided in Table 84.
Table 84. RET cc Instruction Detail
ADL Suffix Operation (if cc is true)
0 None The starting Program Counter is {MBASE, PC[15:0]}.
Pop a 2-byte return address from {MBASE, SPS} into
PC[15:0]. The ADL mode bit remains cleared to 0. The
ending Program Counter is {MBASE, PC[15:0]}.
1 None The starting Program Counter is PC[23:0]. Pop a 3-byte
return address from SPL into PC[23:0]. The ADL mode
bit remains set to 1. The ending Program Counter is
PC[23:0].
0 .S An invalid suffix. RET.L cc must be used in all mixed-
memory mode applications.
1 .S An invalid suffix. RET.L cc must be used in all mixed-
memory mode applications.
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