© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
User manual
Rev. 03 — 7 June 2005
8 of 139
Philips Semiconductors
UM10119
P89LPC938 User manual
[1]
Input/Output for P1.0 to P1.4, P1.6, P1.7. Input for P1.5.
P3.0/XTAL2/
CLKOUT
9
5
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
4
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
3
I
Ground:
0 V reference.
V
DD
21
17
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
TSSOP28,
PLCC28
HVQFN28