z86e54 ZiLOG Semiconductor, z86e54 Datasheet - Page 42

• Manufacturer Part Number: z86e54
• Description: Z8 512 Byte Otp Mcu
• Manufacturer: ZiLOG Semiconductor

PS020102-1003
Software Work Around on the Z86CCPOIZEM Emulator to Enable P27
as Stop-Mode Recovery Source
SWFIXP27:
Note:
Note:
I/O port mode registers are not reconfigured to their default POWER-ON condi-
tions. Thus the I/O, configured as output when the STOP instruction was exe-
cuted, is prevented from glitching to an unknown state. To use the P27 release
approach with STOP mode, use the following instruction:
To enter STOP or HALT mode, it is necessary to first flush the instruction pipeline
to avoid suspending execution in mid-instruction. The user must execute a NOP
(Op Code = FFh) immediately before the appropriate SLEEP instruction, such as:
FFh
6Fh
FFH
7Fh
Any Low level detected on pin P27 takes the device out of
STOP mode, even if it is configured as an output. It is not edge
triggered.
On the CCP emulator, a software workaround must be used to
enable P27 as the Stop-Mode Recovery source. This
workaround follows.
LD
NOP
STOP
Note: X = Dependent on user’s application.
PUSH RP
LD RP, #0Fh
LD R012, #001101X0B
NOP
STOP
or
NOP
HALT
P2M, #1XXX XXXXB
X= 1 for LOW EMI Mode
; clear the pipeline
; enter STOP mode
; clear the pipeline
; enter HALT mode
Z8
®
512 Byte OTP MCU
Z86E54
36