![](http://datasheet.mmic.net.cn/120000/MC68328PV_datasheet_3559354/MC68328PV_10.png)
Signals
2-7
MC68328 USER’S MANUAL 11/6/97
MOTOROLA
SIGNAL
DESCRIPTIONS
2
PRELIMINARY
PK7-PK6/CE1-CE2
These pins can be programmed as either parallel I/O port K7-6 or the PCMCIA 1.0 chip-
enable signals. When programmed as the PCMCIA chip-enables, CE1 and CE2 are active-
low, card-enable signals driven by the MC68328 processor; CE1 enables even bytes; CE2
enables odd bytes. CE1 and CE2 are decoded for assertion by CSD3.
2.1.10 Master SPI Pins
PK0/SPMTXD—MASTER SPI TRANSMIT DATA, PORT K 0
This pin is the master SPI shift register output. By default after reset, this pin becomes
general-purpose input, PK0.
PK1/SPMRXD—MASTER SPI RECEIVE DATA, PORT K 1
This pin is the input to the master SPI shift register. By default after reset, this pin becomes
general-purpose input, PK1.
PK2/SPMCLK—MASTER SPI CLOCK, PORT K 2
This pin is the clock output when the SPIM is enabled. In polarity = 0 mode, this signal is low
while the SPIM is idle. In polarity = 1 mode, this signal is high during idle. By default after
reset, this pin becomes general-purpose input, PK2.
2.1.11 Slave SPI Pins
PK5/SPSCLK—SLAVE SPI CLOCK, PORT K 5
This pin is the slave SPI clock output. By default after reset, this pin becomes general-
purpose input, PK5.
PK4/SPSRXD-SLAVE SPI RECEIVE DATA, PORT K 4
This pin is the slave SPI shift register input. By default after reset, this pin becomes general-
purpose input, PK4.
PK3/SPSSEN-SLAVE SPI ENABLE, PORT K 3
This pin is the slave SPI enable. While this signal is active, 8 clocks shift data into the slave
SPI. This bit is programmable to be active high or low. By default after reset, it becomes
general-purpose input, PK3.
2.1.12 UART Pins
PG0/TXD—UART TRANSMIT DATA, PORT G 0
This pin is the transmitter serial output. While in normal mode, NRZ data is output. While in
IrDA mode, a 3/16 bit-period pulse is output for each “zero” bit transmitted. For RS-232
applications, this pin must be connected to an RS-232 transmitter. For infrared applications,
this pin can directly drive an IR LED or IR transceiver TXD signal. By default after reset, this
pin becomes general-purpose input, PG0.