Real-time clock/system timer – Philips P89LPC903 User Manual
Page 52
Philips Semiconductors
User’s Manual - Preliminary -
P89LPC901/902/903
REAL-TIME CLOCK/SYSTEM TIMER
2003 Dec 8
52
Table 6-1: Real-time Clock/System Timer Clock Source - P89LPC901
FOSC2
(UCFG1.2)
FOSC1
(UCFG1.1)
FOSC0
(UCFG1.0)
RTCS1:0
CCLK Frequency
RTC Clock Frequency
0
0
0
00
High frequency crystal/DIVM
High frequency crystal
(XCLK)
01
10
11
High frequency crystal/DIVM
(CCLK)
0
0
1
00
Medium frequency crystal/DIVM
Medium frequency crystal
(XCLK)
01
10
11
Medium frequency crystal/
DIVM (CCLK)
0
1
0
00
Low frequency crystal/DIVM
Low frequency crystal
(XCLK)
01
10
11
Low frequency crystal/DIVM
(CCLK)
0
1
1
00
RC Oscillator/DIVM
High frequency crystal
(XCLK)
01
Medium frequency crystal
(XCLK)
10
Low frequency crystal
(XCLK)
11
RC Oscillator/DIVM (CCLK)
1
0
0
00
WDT Oscillator/DIVM
High frequency crystal
(XCLK)
01
Medium frequency crystal
(XCLK)
10
Low frequency crystal
(XCLK)
11
WDT Oscillator/DIVM
(CCLK)
1
0
1
xx
undefined
1
1
0
1
1
1
00
external clock/DIVM
external clock
(XCLK)
01
10
11
external clock/DIVM (CCLK)