Intel SA-1100 manual PPC Pin Flag Register

Peripheral Control Module

11.13.7PPC Pin Flag Register

The PPC pin flag register (PPFR) is used to determine which peripherals are currently under the control of the PPC unit. The eight read-only flags denote whether or not each of the peripherals (except serial port 0) is enabled or is disabled and being controlled by the PPC. Note that serial ports 1..3 contain individual enables for their transmit and receive serial engines. Thus, separate flag bits exist for their transmit and receive pins. When a flag is set, it indicates that the corresponding peripheral is disabled and is controlled by the PPC; when it is cleared, it indicates that the peripheral is enabled and its pins are being used for serial transmission (serial ports 1..4) or for LCD operation. Note that for reserved bits, writes are ignored and reads return zero. The following table shows the location of each pin flag bit and to which peripheral pin it corresponds.

Address: 0h 9006 0010										PPFR: PPC Pin Flag Register							Read-Only
Bit	31		30	29		28		27	26	25	24	23	22	21	20	19	18	17	16
										Reserved							SP4	SP3	SP3
																		RX	TX
Reset	0		0	0		0		0	0	0	0	0	0	0	0	0	1	1	1
Bit	15		14	13		12		11	10	9	8	7	6	5	4	3	2	1	0
		SP2	SP2	SP1			SP1						Reserved						LCD
		RX	TX	RX			TX
Reset	1		1	1		1		0	0	0	0	0	0	0	0	0	0	0	1
Bit		Name										Description
0		LCD		LCD controller flag (read-only).
				0	– LCD controller enabled.
				1	– LCD disabled, PPC currently controlling all 12 of its pins: LDD<7:0>, L_PCLK,
				L_LCLK, L_FCLK, L_BIAS.
11..1		—		Reserved.
12		SP1 TX		Serial port 1: SDLC/UART transmit flag (read-only).
				0	– SDLC or UART transmit enabled.
				1	– SDLC and UART transmitters disabled, PPC currently controlling the transmit pin:
				TXD1.
13		SP1 RX		Serial port 1: SDLC/UART receive flag (read-only).
				0	– SDLC or UART receive enabled.
				1	– SDLC and UART receivers disabled, PPC currently controlling the receive pin:
				RXD1.
14		SP2 TX		Serial port 2: ICP transmit flag (read-only).
				0	– HSSP or UART transmit enabled.
				1– HSSP and UART transmitters disabled, PPC currently controlling the transmit pin:
				TXD2.
15		SP2 RX		Serial port 2: ICP receive flag (read-only).
				0	– HSSP or UART receive enabled.
				1	– HSSP and UART receivers disabled, PPC currently controlling the receive pin:
				RXD2.
16		SP3 TX		Serial port 3: UART transmit flag (read-only).
				0	– UART transmit enabled.
				1	– UART transmit disabled, PPC currently controlling the transmit pin: TXD3.
17		SP3 RX		Serial port 3: UART receive flag (read-only).
				0	– UART receive enabled.
				1	– UART receive disabled, PPC currently controlling the receive pin: RXD3.
18		SP4		Serial port 4: MCP/SSP flag (read-only).
				0	– MCP or SSP enabled.
				1– MCP and SSP disabled, PPC currently controlling all 4 of its pins:
						TXD4, RXD4, SCLK, SFRM.
31..19		—		Reserved.

11-192 SA-1100 Developer’s Manual