1 OVERVIEW
S1C31D50/D51 TECHNICAL MANUAL
Seiko Epson Corporation
1-11
(Rev. 2.00)
Pin
name
Assigned
signal
I/O Initial state
Tolerant
fail-safe
structure
Function
Package
48-pin 64-pin 80-pin 100-pin
PD1
SWD
I/O
I (Pull-up)
✓
Serial-wire debugger data input/output
✓ ✓ ✓ ✓
PD1
I/O
I/O port
PD2
PD2
I/O
Hi-Z
–
I/O port
✓ ✓ ✓ ✓
OSC3
A
OSC3 oscillator circuit input
PD3
PD3
I/O
Hi-Z
–
I/O port
✓ ✓ ✓ ✓
OSC4
A
OSC3 oscillator circuit output
PD4
PD4
I/O
Hi-Z
✓
I/O port
– –
✓ ✓
PD5
PD5
I/O
Hi-Z
✓
I/O port
– – –
✓
Note: In the peripheral circuit descriptions, the assigned signal name is used as the pin name.
Universal port multiplexer (UPMUX)
The universal port multiplexer (UPMUX) allows software to select the peripheral circuit input/output function
to be assigned to each pin from those listed below.
Table 1.3.2.2 Peripheral Circuit Input/output Function Selectable by UPMUX
Peripheral circuit
Signal to be assigned I/O
Channel number n
Function
I
2
C
(I2C)
SCLn
I/O n = 0–2
I2C Ch.n clock input/output
SDAn
I/O
I2C Ch.n data input/output
UART
(UART3)
USINn
I
n = 0–2
UART3 Ch.n data input
USOUTn
O
UART3 Ch.n data output
Synchronous serial
interface
(SPIA)
SDIn
I
n = 0–2
SPIA Ch.n data input
SDOn
O
SPIA Ch.n data output
SPICLKn
I/O
SPIA Ch.n clock input/output
#SPISSn
I
SPIA Ch.n slave-select input
16-bit PWM timer
(T16B)
TOUTn0/CAPn0
I/O n = 0, 1
T16B Ch.n PWM output/capture input 0
TOUTn1/CAPn1
I/O
T16B Ch.n PWM output/capture input 1
TOUTn2/CAPn2
I/O
T16B Ch.n PWM output/capture input 2
TOUTn3/CAPn3
I/O
T16B Ch.n PWM output/capture input 3
Note: Do not assign a function to two or more pins simultaneously.