Spi Input/Output Pins - Epson S1C17001 Technical Manual

19 SPI

19.2 SPI Input/Output Pins

Table 19.2.1 lists the SPI pins.
Pin name I/O
SDI (P20) I
SDO (P21) O
SPICLK (P22) I/O
#SPISS (P17) I
The SPI input/output pins (SDI, SDO, SPICLK, #SPISS) are shared with general purpose input/output port pins (P20,
P21, P22, P17) and are initially set as general purpose input/output port pins. The function must be switched using
the P2_PMUX and P1_PMUX register settings to use general purpose input/output port pins as SPI input/output
pins. Switch the pins to SPI mode by setting the following control bits to 1.
P20 → SDI
∗ P20MUX: P20 Port Function Select Bit in the P2 Port Function Select (P2_PMUX) Register (D0/0x52a2)
P21 → SDO
∗ P21MUX: P21 Port Function Select Bit in the P2 Port Function Select (P2_PMUX) Register (D1/0x52a2)
P22 → SPICLK
∗ P22MUX: P22 Port Function Select Bit in the P2 Port Function Select (P2_PMUX) Register (D2/0x52a2)
P17 → #SPISS
∗ P17MUX: P17 Port Function Select Bit in the P1 Port Function Select (P1_PMUX) Register (D7/0x52a1)
For detailed information on pin function switching, refer to "10.2 Input/Output Pin Function Selection (Port
MUX)."
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Table 19.2.1: SPI pin list
Qty
1 SPI data input pin
Inputs serial data from SPI bus.
1 SPI data output pin
Outputs serial data to SPI bus.
1 SPI external clock input/output pin
Outputs SPI clock when SPI is in Master mode.
Inputs external clock when SPI is used in Slave mode.
1 SPI slave selection signal (active Low) input pin
SPI (Slave mode) is selected as slave device by Low input to this pin.
EPSON
Function
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