Nxp semiconductors – NXP Semiconductors P89LPC9321 UM10310 User Manual
Page 7
UM10310
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User manual
Rev. 2 — 1 November 2010
7 of 139
NXP Semiconductors
UM10310
P89LPC9321 User manual
[1]
Input/output for P1.0 to P1.4, P1.6, P1.7. Input for P1.5.
P2.5/SPICLK
16
I/O
P2.5 — Port 2 bit 5.
I/O
SPICLK — SPI clock. When configured as master, this pin is output; when
configured as slave, this pin is input.
P2.6/OCA
27
I/O
P2.6 — Port 2 bit 6.
O
OCA — Output Compare A.
P2.7/ICA
28
I/O
P2.7 — Port 2 bit 7.
I
ICA — Input Capture A.
P3.0 to P3.1
I/O
Port 3: Port 3 is a 2-bit I/O port with a user-configurable output type. During reset
Port 3 latches are configured in the input only mode with the internal pull-up
disabled. The operation of Port 3 pins as inputs and outputs depends upon the
port configuration selected. Each port pin is configured independently. Refer to
Section 4.1 “Port configurations”
for details.
All pins have Schmitt triggered inputs.
Port 3 also provides various special functions as described below:
P3.0/XTAL2/
CLKOUT
9
I/O
P3.0 — Port 3 bit 0.
O
XTAL2 — Output from the oscillator amplifier (when a crystal oscillator option is
selected via the flash configuration.
O
CLKOUT — CPU clock divided by 2 when enabled via SFR bit (ENCLK -TRIM.6).
It can be used if the CPU clock is the internal RC oscillator, watchdog oscillator or
external clock input, except when XTAL1/XTAL2 are used to generate clock
source for the RTC/system timer.
P3.1/XTAL1
8
I/O
P3.1 — Port 3 bit 1.
I
XTAL1 — Input to the oscillator circuit and internal clock generator circuits (when
selected via the flash configuration). It can be a port pin if internal RC oscillator or
watchdog oscillator is used as the CPU clock source, and if XTAL1/XTAL2 are not
used to generate the clock for the RTC/system timer.
V
SS
7
I
Ground: 0 V reference.
V
DD
21
I
Power supply: This is the power supply voltage for normal operation as well as
Idle and Power-down modes.
Table 1.
Pin description
…continued
Symbol
Pin
Type
Description