External Signals
MOTOROLA
MPC823 USER’S MANUAL
2-9
EXTERNAL
SIGNALS
2
PA[5]
CLK3
TIN2
L1TCLKA
BRGO2
T6
General-Purpose I/O Port A Bit 5—Bit 5 of the general-purpose I/O port A.
CLK3—This input signal is one of the four clock pins that can be used to clock the
serial communication controller, serial management controllers, and USB.
TIN2—The timer 2 external clock input pin.
L1TCLKA—The transmit clock for the serial interface time-division multiplex port A.
BRGO2—The output clock of BRG2.
PA[4]
CLK4
TOUT2
TIN4
R6
General-Purpose I/O Port A Bit 4—Bit 4 of the general-purpose I/O port A.
CLK4—This input signal is one of the four clock pins that can be used to clock the
serial communication controller, serial management controllers, and USB.
TOUT2—The timer 2 output pin.
TIN4—The timer 4 external clock pin.
PB[31]
SPISEL
LCD_A
N14
General-Purpose I/O Port B Bit 31—Bit 31 of the general-purpose I/O port B.
SPISEL—The serial peripheral interface slave select input pin.
LCD_A—This is one of the LCD controller’s three extension data bits, which are
used to drive an active LCD panel. When using a 12-bit bus instead of a 9-bit bus,
the LCD_A signal is the least-significant bit of the red 4-bit code. The red portion of
the bus consists of LD[0:2] and LCD_A.
PB[30]
SPICLK
P15
General-Purpose I/O Port B Bit 30—Bit 30 of the general-purpose I/O port B.
SPICLK—The serial peripheral interface output clock when it is configured as a
master or serial peripheral interface input clock when it is configured as a slave.
PB[29]
SPIMOSI
P14
General-Purpose I/O Port B Bit 29—Bit 29 of the general-purpose I/O port B.
SPIMOSI—The serial peripheral interface output data when it is configured as a
master or serial peripheral interface input data when it is configured as a slave.
PB[28]
SPIMISO
BRGO3
T15
General-Purpose I/O Port B Bit 28—Bit 28 of the general-purpose I/O port B.
SPIMISO—The serial peripheral interface input data when it is configured as a
master or serial peripheral interface output data when it is configured as a slave.
BRGO3—The output clock of BRG3.
PB[27]
I2CSDA
BRGO1
T14
General-Purpose I/O Port B Bit 27—Bit 27 of the general-purpose I/O port B.
I2CSDA—The I2C serial data pin. This pin is bidirectional and should be configured
as an open-drain output.
BRGO1—The output clock of BRG1.
PB[26]
I2CSCL
BRGO2
P12
General-Purpose I/O Port B Bit 26—Bit 26 of the general-purpose I/O port B.
I2CSCL—The I2C serial clock pin. This pin is bidirectional and should be configured
as an open-drain output.
BRGO2—The output clock of BRG2.
PB[25]
SMTXD1
N11
General-Purpose I/O Port B Bit 25—Bit 25 of the general-purpose I/O port B.
SMTXD1—The serial management controller 1 transmit data output pin.
PB[24]
SMRXD1
T11
General-Purpose I/O Port B Bit 24—Bit 24 of the general-purpose I/O port B.
SMRXD1—The serial management controller 1 receive data input pin.
PB[23]
SMSYN1
SDACK1
T10
General-Purpose I/O Port B Bit 23—Bit 23 of the general-purpose I/O port B.
SMSYN1—The serial management controller 1 external sync input pin.
SDACK1—The SDMA acknowledge 1 output pin that is used as a peripheral
interface signal for IDMA emulation or as a CAM interface signal for Ethernet.
PB[22]
SMSYN2
SDACK2
R9
General-Purpose I/O Port B Bit 22—Bit 22 of the general-purpose I/O port B.
SMSYN2—The serial management controller 2 external sync input pin.
SDACK2—The SDMA acknowledge 2 output pin that is used as a peripheral
interface signal for IDMA emulation or as a CAM interface signal for Ethernet.
PB[19]
L1ST1
LCD_B
R7
General-Purpose I/O Port B Bit 19—Bit 19 of the general-purpose I/O port B.
L1ST1—One of eight output strobes that can be generated by the serial interface.
LCD_B—This is one of the LCD controller’s three extension data bits, which are
used to drive an active LCD panel. When using a 12-bit bus instead of a 9-bit bus,
the LCD_B signal is the least-significant bit of the green 4-bit code. The green portion
of the bus consists of LD[3:5] and LCD_B.
Table 2-1. Signal Descriptions (Continued)
SIGNAL
PIN NUMBER
DESCRIPTION