AT89LP216-20PI ATMEL [ATMEL Corporation], AT89LP216-20PI Datasheet - Page 26

• Manufacturer Part Number: AT89LP216-20PI
• Description: Microcontroller with 2K Bytes Flash
• Manufacturer: ATMEL [ATMEL Corporation]

13.4
26
Port Alternate Functions
AT89LP216 [Preliminary]
Most general-purpose digital I/O pins of the AT89LP216 share functionality with the various I/Os
needed for the peripheral units.
functions are connected to the pins in a logic AND fashion. In order to enable the
alternate function on a port pin, that pin must have a “1” in its corresponding port register bit,
otherwise the input/output will always be “0”. Furthermore, each pin must be configured
for the correct input/output mode as required by its peripheral before it may be used as such.
Table 13-4
Table 13-4.
Table 13-5.
Port Pin
P1.0
P1.1
P1.2
P1.3
P1.4
P1.5
P1.6
P1.7
P3.0
P3.1
P3.2
P3.3
P3.4
P3.5
P3.6
PxM0.y
0
0
1
1
shows how to configure a generic pin for use with an alternate function.
Alternate Function Configurations for Pin y of Port x
Port Pin Alternate Functions
PxM0.y
P1M0.0
P1M0.1
P1M0.2
P1M0.3
P1M0.4
P1M0.5
P1M0.6
P1M0.7
P3M0.0
P3M0.1
P3M0.2
P3M0.3
P3M0.4
P3M0.5
Configuration Bits
not configurable
PxM1.y
0
1
0
1
Table 13-5
PxM1.y
P1M1.0
P1M1.1
P1M1.2
P1M1.3
P1M1.4
P1M1.5
P1M1.6
P1M1.7
P3M1.0
P3M1.1
P3M1.2
P3M1.3
P3M1.4
P3M1.5
lists the alternate functions of the port pins. Alternate
Px.y
Alternate
CMPOUT
Function
CLKOUT
X
1
1
1
MOSI
MISO
GPI0
GPI1
GPI2
GPI3
GPI4
GPI5
GPI6
GPI7
AIN0
AIN1
RXD
INT0
INT1
SCK
TXD
SS
T0
T1
Notes
input-only
input-only
Internal RC Oscillator Only
Internal RC Oscillator or
External Clock Source Only
Pin is tied to comparator output
I/O Mode
bidirectional (internal pull-up)
output
input
bidirectional (external pull-up)
RST must be disabled
3621A–MICRO–6/06