S3C72P9 Datasheet, PDF (197/225 Pages) Samsung semiconductor – SINGLE-CHIP MICROCONTROLLER HAS BEEN DESIGNED FOR HIGH PERFORMANCE USING

S3C72P9/P72P9 (Preliminary Spec)
SERIAL I/O INTERFACE
+ PROGRAMMING TIP — Setting Transmit/Receive Modes for Serial I/O (Continued)
4. Transmit and receive an external clock in LSB-first mode:
Input
INTS
BITS
SMB
LD
LD
LD
LD
LD
LD
BITS
EI
BITS
.
.
PUSH
PUSH
LD
SMB
XCH
SMB
LD
BITS
POP
POP
IRET
EMB
15
EA,#02H
PMG1,EA
EA,#07H
SMOD,EA
EA,TDATA
SBUF,EA
SMOD.3
IES
SB
EA
EA,TDATA
15
EA,SBUF
0
RDATA,EA
SMOD.3
EA
SB
; P0.1 / SO ← Output, P0.0 / SCK and P0.2 / SI ←
; SIO start
; Store SMB, SRB
; Store EA
; EA ← Transmit data
; EA ← Receive data
; RDATA ← Receive data
; SIO start
SCK/P0.0
SO/P0.1
SI/P0.2
External
Device
[S3C72P9]
High Speed SIO Transmission
13-7