UM10310_1 © NXP B.V. 2008. All rights reserved.
User manual Rev. 01 — 1 December 2008 46 of 139
NXP Semiconductors UM10310
P89LPC9321 User manual
010 0 00 Low frequency crystal Low frequency crystal
/DIVM
01
10
11 Low frequency crystal
/DIV
1 00 Low frequency crystal Internal RC oscillator
01
10
11 Internal RC oscillator
011 0 00 High frequency crystal Internal RC oscillator
/DIVM
01 Medium frequency crystal
10 Low frequency crystal
11 Internal RC oscillator
/DIVM
1 00 High frequency crystal Internal RC oscillator
01 Medium frequency crystal
10 Low frequency crystal
11 Internal RC oscillator
100 0 00 High frequency crystal Watchdog oscillator
/DIVM
01 Medium frequency crystal
10 Low frequency crystal
11 Watchdog oscillator /DIVM
1 00 High frequency crystal Internal RC oscillator
01 Medium frequency crystal
10 Low frequency crystal
11 Internal RC oscillator
101 x xx undefined undefined
110 x xx undefined undefined
111 0 00 External clock input External clock input
/DIVM
01
10
11 External clock input /DIVM
1 00 External clock input Internal RC oscillator
01
10
11 Internal RC oscillator
Table 31. Real-time Clock Control register (RTCCON - address D1h) bit allocation
Bit 7 6 5 4 3 2 1 0
Symbol RTCF RTCS1 RTCS0 - - - ERTC RTCEN
Reset011xxx00
Table 30. Real-time Clock/System Timer clock sources …continued
FOSC2:0 RCCLK RTCS1:0 RTC clock source CPU clock source