14 SYNCHRONOUS SERIAL INTERFACE (SPIA)
S1C31D50/D51 TECHNICAL MANUAL
Seiko Epson Corporation
14-1
(Rev. 2.00)
14 Synchronous Serial Interface (SPIA)
14.1 Overview
SPIA is a synchronous serial interface. The features of SPIA are listed below.
• Supports both master and slave modes.
• Data length: 2 to 16 bits programmable
• Either MSB first or LSB first can be selected for the data format.
• Clock phase and polarity are configurable.
• Supports full-duplex communications.
• Includes separated transmit data buffer and receive data buffer registers.
• Can generate receive buffer full, transmit buffer empty, end of transmission, and overrun interrupts.
• Can issue a DMA transfer request when a receive buffer full or a transmit buffer empty occurs.
• Master mode allows use of a 16-bit timer to set baud rate.
• Slave mode is capable of being operated with the external input clock SPICLK
n
only.
• Slave mode is capable of being operated in SLEEP mode allowing wake-up by an SPIA interrupt.
• Input pins can be pulled up/down with an internal resistor.
Figure 14.1.1 shows the SPIA configuration.
Table 14.1.1 SPIA Channel Configuration of S1C31D50/D51
Item
48-pin package
64-pin package
80-pin package
100-pin package
Number of channels
3 channels (Ch.0 to Ch.2)
Internal clock input
Ch.0
←
16-bit timer Ch.1
Ch.1
←
16-bit timer Ch.6
Ch.2
←
16-bit timer Ch.5
SPIA Ch.n
Timer
CPU core
Clock/shift register
control circuit
Pull-up/down control
circuit
16-bit timer
Underflow
(Used only in slave mode)
Receive data buffer
RXD[15:0]
Shift register
Transmit data buffer
TXD[15:0]
Interrupt
control circuit
SDIn
SDOn
SPICLKn
#SPISSn
1/2
CPOL
PUEN
Clock
generator
CLK_SPIAn
Inter
nal data
bu
s
TENDIE
RBFIE
TBEIE
TENDIF
RBFIF
TBEIF
MODEN
SFTRST
LSBFST
CPHA
NOCLKDIV
CLK_T16_m
V
SS
V
DD
V
DD
V
DD
DMA
controller
DMA request
control circuit
RBFDMAENx
TBEDMAENx
Figure 14.1.1 SPIA Configuration