
III PERIPHERAL BLOCK: INPUT/OUTPUT PORTS
B-III-10-4
EPSON
S1C33T01 FUNCTION PART
I/O Ports (P Ports)
Structure of I/O Port
The Peripheral Block contains 69 bits of I/O ports (P00 to P07, P10 to P16, P20 to P27, P30 to P35, P40 to P47, P50
to P57, P60 to P67, P70 to P77, P80 to P87) that can be directed for input or output through the use of a program.
Figure 10.2 shows the structure of a typical I/O port.
VDDE
VSS
Internal
data
bus
Pxx
Data
register
Peripheral circuit
input
Peripheral circuit
output
I/O control
register
Function
select register
Figure 10.2
Structure of I/O Port
I/O Port Pins
The I/O ports concurrently serve as the input/output pins for peripheral circuits, as shown in Table 10.3. Whether
they are used as I/O ports or for peripheral circuits can be set bit-for-bit using a function select register. All pins not
used for peripheral circuits can be used as general-purpose I/O ports.
Table 10.3
I/O Pins
Pin name
I/O
Pull-up
Function
Function select bit
P00/SIN0
I/O
–
I/O port / Serial IF Ch.0 data input
CFP00(D0)/P0 function select register(0x402D0)
P01/SOUT0
I/O
–
I/O port / Serial IF Ch.0 data output
CFP01(D1)/P0 function select register(0x402D0)
P02/#SCLK0
I/O
–
I/O port / Serial IF Ch.0 clock input/output
CFP02(D2)/P0 function select register(0x402D0)
P03/#SRDY0
I/O
–
I/O port / Serial IF Ch.0 ready input/output
CFP03(D3)/P0 function select register(0x402D0)
P04/SIN1/
#DMAACK2
I/O
–
I/O port / Serial IF Ch.1 data input /
#DMAACK2 output (Ex)
CFP04(D4)/P0 function select register(0x402D0)
CFEX4(D4)/Port function extension register(0x402DF)
P05/SOUT1/
#DMAEND2
I/O
–
I/O port / Serial IF Ch.1 data output /
#DMAEND2 output (Ex)
CFP05(D5)/P0 function select register(0x402D0)
CFEX5(D5)/Port function extension register(0x402DF)
P06/#SCLK1/
#DMAACK3
I/O
–
I/O port / Serial IF Ch.1 clock input/output /
#DMAACK3 output (Ex)
CFP06(D6)/P0 function select register(0x402D0)
CFEX6(D6)/Port function extension register(0x402DF)
P07/#SRDY1/
#DMAEND3
I/O
–
I/O port / Serial IF Ch.1 ready input/output /
#DMAEND3 output (Ex)
CFP07(D7)/P0 function select register(0x402D0)
CFEX7(D7)/Port function extension register(0x402DF)
P10/EXCL0/
T8UF0/DST0
I/O
–
I/O port / 16-bit timer 0 event counter input (I) /
8-bit timer 0 output (O) / DST0 output (Ex)
CFP10(D0)/P1 function select register(0x402D4)
CFEX1(D1)/Port function extension register(0x402DF)
P11/EXCL1/
T8UF1/DST1
I/O
–
I/O port / 16-bit timer 1 event counter input (I) /
8-bit timer 1 output (O) / DST1 output (Ex)
CFP11(D1)/P1 function select register(0x402D4)
CFEX1(D1)/Port function extension register(0x402DF)
P12/EXCL2/
T8UF2/DST2
I/O
–
I/O port / 16-bit timer 2 event counterinput (I) /
8-bit timer 2 output (O) / DST2 output (Ex)
CFP12(D2)/P1 function select register(0x402D4)
CFEX0(D0)/Port function extension register(0x402DF)
P13/EXCL3/
T8UF3/DPCO
I/O
–
I/O port / 16-bit timer 3 event counter input (I) /
8-bit timer 3 output (O) / DPCO output (Ex)
CFP13(D3)/P1 function select register(0x402D4)
CFEX1(D1)/Port function extension register(0x402DF)
P14/FOSC1/
DCLK
I/O
–
I/O port / Low-speed (OSC1) clock output /
DCLK output (Ex)
CFP14(D4)/P1 function select register(0x402D4)
CFEX0(D0)/Port function extension register(0x402DF)
P15/EXCL4/
#DMAEND0
I/O
–
I/O port / 16-bit timer 4 event counter input (I) /
#DMAEND0 output (O)
CFP15(D5)/P1 function select register(0x402D4)
P16/EXCL5/
#DMAEND1
I/O
–
I/O port / 16-bit timer 5 event counter input (I) /
#DMAEND1 output (O)
CFP16(D6)/P1 function select register(0x402D4)
(I): Input mode, (O): Output mode, (Ex): Extended function
: A 3-V system I/O voltage can only be used for the P10–P14 pins.