Intel SA-1100 Computer Hardware User Manual


 
11-192 SA-1100
Developer’s Manual
Peripheral Control Module
11.13.7 PPC 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 3130292827262524232221 2019 18 1716
Reserved SP4
SP3
RX
SP3
TX
Reset00000000000 00 1 11
Bit 151413121110 9 8 7 6 5 4 3 2 1 0
SP2
RX
SP2
TX
SP1
RX
SP1
TX
Reserved LCD
Reset11110000000 00 0 01
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.