Samsung S3C80M4/F80M4 User Manual page 196

CLOCK CIRCUIT
STOP CONTROL REGISTER (STPCON)
The STOP control register, STPCON, is located in the bank 0 of set1, address FBH. It is read/write addressable
and has the following functions:
— Enable/Disable STOP instruction
After a reset, the STOP instruction is disabled, because the value of STPCON is "other values".
If necessary, you can use the STOP instruction by setting the value of STPCON to "10100101B".
PROGRAMMING TIP — How to Use Stop Instruction
This example shows how to go STOP mode when a main clock is selected as the system clock.
LD
STOP
NOP
NOP
NOP
LD
7-6
STOP Control Register (STPCON)
FBH, Set 1,bank 0, R/W
MSB .7 .6 .5
STOP Control bits:
Other values = Disable STOP instruction
10100101 = Enable STOP instruction
NOTE: Before executing the STOP instruction, set the STPCON
register as "10100101b". Otherwise the STOP instruction
will not be executed and reset will be generated.
Figure 7-8. STOP Control Register (STPCON)
STOPCON,#1010010B
STOPCON,#00000000B
.4 .3 .2 .1
; Enable STOP instruction
; Enter STOP mode
; Release STOP mode
; Disable STOP instruction
S3C80M4/F80M4
.0 LSB