Samsung KS57C2308 Manual page 274

SERIAL I/O INTERFACE
SI
IRQS
SCK
P0.1/
TOL0
CPU CLK
10
fxx/2
4
fxx/2
SMOD.7 SMOD.6 SMOD.5
* Instruction Execution
fxx: System Clock
13-2
CLOCK
R
SELECTOR
S
Figure 13-1. Serial I/O Interface Circuit Diagram
INTERNAL BUS
8
SBUF (8-BIT)
R
Q D
CK
Q
-
SMOD.3 SMOD.2 SMOD.1
8
INTERNAL BUS
KS57C2308/P2308/C2316/P2316
LSB or MSB first
OVERFLOW
Q0 Q1 Q2
3-BIT COUNTER
CLEAR
BITS*
SO
SMOD.0