KS57C2308/P2308/C2316/P2316
SERIAL I/O INTERFACE
13-5
SERIAL I/O BUFFER REGISTER (SBUF)
The serial I/O buffer register, SBUF, can be read or written using 8-bit RAM control instructions. Following a
RESET
, the value of SBUF is undetermined.
When the serial interface operates in transmit-and-receive mode (SMOD.1 = "1"), transmit data in the SIO buffer
register are output to the SO pin (P0.2) at the rate of one bit for each falling edge of the SIO clock. Receive data
are simultaneously input from the SI pin (P0.3) to SBUF at the rate of one bit for each rising edge of the SIO
clock. When receive-only mode is used, incoming data are input to the SIO buffer at the rate of one bit for each
rising edge of the SIO clock.
+
+
PROGRAMMING TIP — Setting Transmit/Receive Modes for Serial I/O
1.
Transmit the data value 48H through the serial I/O interface using an internal clock frequency of fxx/2
4
and in MSB-first mode:
BITS
EMB
SMB
15
LD
EA,#48H
;
LD
SBUF,EA
;
LD
EA,#0EEH
LD
SMOD,EA
; SIO data transfer
KS57C2308/C2316
/ P0.1
SO / P0.2
EXTERNAL
DEVICE
SCK
2.
Use CPU clock to transfer and receive serial data at high speed:
BITR
EMB
LD
EA,TDATA
; TDATA address = BANK0 (20H–7FH)
LD
SBUF,EA
LD
EA,#4FH
LD
SMOD,EA
; SIO start
BITS
IES
STEST
BTSTZ
IRQS
JR
STEST
LD
EA,SBUF
SMB
0
LD
RDATA,EA
; RDATA address = BANK0 (20H–7FH)
Summary of Contents for KS57C2308
Page 30: ...ADDRESS SPACES KS57C2308 P2308 C2316 P2316 2 22 NOTES ...
Page 168: ...SAM47 INSTRUCTION SET KS57C2308 P2308 C2316 P2316 5 94 NOTES ...
Page 170: ......
Page 206: ...POWER DOWN KS57C2308 P2308 C2316 P2316 8 8 NOTES ...
Page 210: ...RESET KS57C2308 P2308 C2316 P2316 9 4 NOTES ...
Page 222: ...I O PORTS KS57C2308 P2308 C2316 P2316 10 12 NOTES ...
Page 272: ...LCD CONTROLLER DRIVER KS57C2308 P2308 C2316 P2316 12 24 NOTES ...
Page 280: ...SERIAL I O INTERFACE KS57C2308 P2308 C2316 P2316 13 8 NOTES ...
Page 294: ...MECHANICAL DATA KS57C2308 P2308 C2316 P2316 15 2 NOTES ...
Page 310: ...KS57P2308 P2316 OTP KS57C2308 P2308 C2316 P2316 16 16 NOTES ...
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