Intel SA-1100 manual Dedicated Peripheral Pins, Peripheral Gpio Pin Function

Peripheral Control Module

11.4Peripheral Pins

Each peripheral has a number of dedicated pins with which to communicate to off-chip devices. The six peripherals of the SA-1100 use a total of 24 pins: the LCD uses twelve pins; serial port 4 four pins; and serial port 0 through 3 each use two pins. Many applications may not require the use of all six of the SA-1100’s peripherals. To provide maximum flexibility, the pins associated with any unused peripheral (except serial port 0) can be used as general-purpose digital input/output pins that are noninterruptible. When a peripheral is disabled, the peripheral pin controller (PPC) automatically takes control of the peripheral’s pin direction and pin state. A user can sample input pin state by reading the PPC pin state register (PPSR) and control the state of an output pin by writing to it. Pin direction is established by configuring the PPC pin direction register (PPDR). Table 11-4shows a list of the pins associated with the peripheral units.

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Table 11-4. Dedicated Peripheral Pins

Peripheral	GPIO Pin	Function
	L_PCLK	Pixel clock
	L_LCLK	Line clock/horizontal sync pulse
LCD Controller
	L_FCLK	Frame clock/vertical sync pulse
	L_BIAS	A/C bias signal
	LDD<7:0>	Pixel data
Serial port 0: USB	UDC+	Positive differential receiver
	UDC-	Negative differential receiver
Serial port 1: SDLC/UART	TXD_1	Serial transmit data
	RXD_1	Serial receive data
Serial port 2: ICP	TXD_2	Serial transmit data
	RXD_2	Serial receive data
Serial port 3: UART	TXD_3	Serial transmit data
	RXD_3	Serial receive data
	TXD_C	Serial transmit data
Serial port 4: MPC/SSP	RXD_C	Serial receive data
	SCLK_C	Serial clock
	SFRM_	Serial frame clock

SA-1100 Developer’s Manual 11-5