Stop Control Register (Stpcon); How To Use Stop Instruction - Samsung S3C9228 User Manual

S3C9228/P9228_UM_REV1.10

STOP CONTROL REGISTER (STPCON)

The STOP control register, STPCON, is located in address E0H. 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
Stop Control Register (STPCON)
MSB .7 .6 .5
STOP control bits:
10100101 = Enable STOP instruction
Other values = Disable STOP instruction
Figure 7-9. STOP Control Register (STPCON)
STOPCON,#1010010B
STOPCON,#00000000B
E0H, R/W
.4 .3 .2 .1
; Enable STOP instruction
; Enter STOP mode
; Release STOP mode
; Disable STOP instruction
CLOCK CIRCUITS
.0 LSB
7-7