1.0 SIGNAL DESCRIPTION
Port 0 (P0.0 - P0.7):Port 0 is an 8-bit input only port when used
in its default mode. When configured for their alternate function,
five of the bits are bi-directional EDAC check bits as shown in
Table 1.
Table 2. Port 1 Alternate Functions
Port
Pin
Alternate
Name
Alternate Function
P1.0
P1.1
P1.2
P1.3
P1.0
P1.1
I/O Pin
Port 1 (P1.0 - P1.7): Port 1 is an 8-bit, quasi-bidirectional, I/O
port. All pins are quasi-bidirectional unless the alternate
function is selected per Table 2. When the pins are configured
for their alternate functions, they act as standard I/O, not quasi-
bidirectional.
I/O Pin
I/O Pin
P1.2
PWM1
Setting IOC3.2=1 enables P1.3 as
the Pulse Width Modulator
(PWM1) output pin.
Port 2 (P2.0 - P2.7):Port 2 is an 8-bit, multifunctional, I/O port.
These pins are shared with timer 2 functions, serial data I/O and
PWM0 output, per Table 3.
P1.4
P1.5
PWM2
BREQ
Setting IOC3.3=1 enables P1.4 as
the Pulse Width Modulator
(PWM2) output pin.
AD0-AD7: The lower 8-bits of the multiplexed address/data
bus. The pins on this port are bidirectional during the data phase
of the bus cycle.
Bus Request, output activated
when the bus controller has a
pending external memory cycle.
AD8-AD15: The upper 8-bits of the multiplexed address/data
bus. The pins on this port are bidirectional during the data phase
of the 16-bit bus cycle. When running in 8-bit bus width, these
pins are non-multiplexed, dedicated upper address bit outputs.
P1.6
P1.7
HLDA
HOLD
Bus Hold Acknowledge, output
indicating the release of the bus.
HSI: Inputs to the High Speed Input Unit. Four HSI pins are
available: HSI.0, HSI.1, HSI.2, and HSI.3. Two of these pins
(HSI.2 and HSI.3) are shared with the HSO Unit. Two of these
pins (HSI.0 and HSI.1) have alternate functions for Timer 2.
Bus Hold, input requesting control
of the bus.
Table 3. Port 2 Alternate Functions
Port
Pin
Alternate
Name
Alternate Function
HSO: Outputs from the High Speed Output Unit. Six HSO pins
are available: HSO.0, HSO.1, HSO.2, HSO.3, HSO.4, and
HSO.5. Pins HSO.4 and HSO.5 are shared with pins HSI.2 and
HSI.3 of the HSI Unit respectively.
P2.0
P2.1
P2.2
TXD
RXD
Transmit Serial Data.
Receive Serial Data.
EXTINT
External interrupt. Clearing
IOC1.1 will allow P2.2 to be
used for EXTINT (INT07)
Table 1. Port 0 Alternate Functions
P2.3
T2CLK
Timer 2 clock input and Serial
port baud rate generator input.
Port Pin
Alternate
Name
Alternate Function
P2.4
P2.5
T2RST
PWM0
Timer 2 Reset
P0.0-P0.3,
P0.6
ECB0-ECB4 Error Detection & Correction
Check Bits
Pulse Width Modulator
output 0
P0.4
P0.5
Input Port Pins
P2.6
P2.7
T2UP-DN
Controls the direction of the
Timer 2 counter. Logic High
equals count down. Logic low
equals count up.
P0.7
EXTINT
Setting IOC1.1=1 will allow P0.7
to be used for EXTINT (INT07)
T2CAPTURE A rising edge on P2.7 causes
the value of Timer 2 to be
captured into this register, and
generates a Timer 2 Capture
interrupt (INT11).
2
AEROFLEX [ AEROFLEX CIRCUIT TECHNOLOGY ]
