P89LPC915 PHILIPS [NXP Semiconductors], P89LPC915 Datasheet - Page 38

• Manufacturer Part Number: P89LPC915
• Description: 8-bit microcontrollers with accelerated two-clock 80C51 core 2 kB 3 V Flash with 8-bit A/D converter
• Manufacturer: PHILIPS [NXP Semiconductors]

Philips Semiconductors
9397 750 14397
Product data
9.12.1 Port configurations
9.12.2 Quasi-bidirectional output configuration
9.12 I/O ports
The P89LPC916 and P89LPC917 devices have three I/O ports: Port 0, Port 1, and
Port 2. The exact number of I/O pins available depends on the clock and reset options
chosen, as shown in
Table 10:
[1]
The P89LPC915 has 2I/O ports: Port 0, and Port 1. The exact number of I/O pins
available depends on the reset option chosen, as shown in
Table 11:
[1]
Except as listed below, every I/O pin on the P89LPC915/916/917 may be configured
by software to one of four types on a bit-by-bit basis. These are: quasi-bidirectional
(standard 80C51 port outputs), push-pull, open drain, and input-only. Two
configuration registers for each port select the output type for each port pin.
P1.5/RST can only be an input and cannot be configured.
SCL/T0/P1.2 and SDA/INTO/P1.3 may only be configured to be either input-only or
open drain.
Quasi-bidirectional output type can be used as both an input and output without the
need to reconfigure the port. This is possible because when the port outputs a logic
HIGH, it is weakly driven, allowing an external device to pull the pin LOW. When the
Clock source
RC oscillator or Watchdog oscillator No external reset (except during
External clock input
Clock source
RC oscillator or Watchdog oscillator No external reset (except during
External clock input
Required for operation above 12 MHz.
Required for operation above 12 MHz.
Number of I/O pins available (P89LPC916, P89LPC917)
Number of I/O pins available (P89LPC915)
Rev. 04 — 17 December 2004
8-bit microcontrollers with accelerated two-clock 80C51 core
Table
10.
Reset option
power-up)
External RST pin supported
No external reset (except during
power-up)
External RST pin supported
Reset option
power-up)
External RST pin supported
No external reset (except during
power-up)
External RST pin supported
P89LPC915/916/917
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
Table
[1]
[1]
11.
Number of
I/O pins
(16-pin
package)
14
13
13
12
Number of
I/O pins
(14-pin
package)
12
11
11
10
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