I/o ports, Nxp semiconductors – NXP Semiconductors P89LPC9321 UM10310 User Manual
Page 28
UM10310
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User manual
Rev. 2 — 1 November 2010
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NXP Semiconductors
UM10310
P89LPC9321 User manual
4. I/O
ports
The P89LPC9321 has four I/O ports: Port 0, Port 1, Port 2, and Port 3. Ports 0, 1,and 2
are 8-bit ports, and Port 3 is a 2-bit port. The exact number of I/O pins available depends
upon the clock and reset options chosen (see
Fig 9.
Interrupt sources, interrupt enables, and power-down wake-up sources.
002aae160
IE0
EX0
IE1
EX1
BOIF
EBO
KBIF
EKBI
interrupt
to CPU
wake-up
(if in power-down)
EWDRT
CMF2
CMF1
EC
EA (IE0.7)
TF1
ET1
TI & RI/RI
ES/ESR
TI
EST
SI
EI2C
SPIF
ESPI
RTCF
ERTC
(RTCCON.1)
WDOVF
TF0
ET0
any CCU interrupt
ECCU
EEIF
EIEE
Table 12.
Number of I/O pins available
Clock source
Reset option
Number of I/O
pins
On-chip oscillator or watchdog
oscillator
No external reset (except during power up) 26
External RST pin supported
25
External clock input
No external reset (except during power up) 25
External RST pin supported
24
Low/medium/high speed oscillator
(external crystal or resonator)
No external reset (except during power up) 24
External RST pin supported
23