PC87591E Datasheet, PDF (143/437 Pages) National Semiconductor (TI) – LPC Mobile Embedded Controllers

Embedded Controller Modules (Continued)
Timer/Counter Register 2 (TnCNT2)
The TnCNT2 register is a word-wide read/write register that is not altered by reset. The power-up value is unknown.
Location: MFT16 1: 00 FD86₁₆
MFT16 2: 00 FDA6₁₆
Type: R/W
Bit
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Name
TCNT2
Clock Pre-Scaler Register (TnPRSC)
The TnPRSC register is a byte-wide read/write register. It contains the current value of the clock pre-scaler, CLKPS. The
register is cleared on reset. It defines the timer clock pre-scaler ratio.
Location: MFT16 1: 00 FD88₁₆
MFT16 2: 00 FDA8₁₆
Type: R/W
Bit
Name
Reset
7
6
5
4
3
2
1
0
Reserved
CLKPS
0
0
0
0
0
0
0
0
Bit
Description
4-0 CLKPS (Clock Pre-Scaler). The timer clock is generated by dividing the system clock by CLKPS+1. Therefore
the maximum timer clock frequency is equal to the system clock (CLKPS=00000) and the minimum timer clock
is the system clock divided by 32 (CLKPS=11111).
7-5 Reserved.
Clock Unit Control Register (TnCKC)
The TnCKC register is a byte-wide read/write register. It defines the clock source selection for each timer counter. The reg-
ister is cleared on reset, thus disabling timer/counter 1 and timer/counter 2 clocks.
Location: MFT16 1: 00 FD8A₁₆
MFT16 2: 00 FDAA₁₆
Type: R/W
Bit
Name
Reset
7
6
Reserved
0
0
5
4
3
C2CSEL
0
0
0
2
1
0
C1CSEL
0
0
0
Bit
Description
2-0 C1CSEL (Counter 1 Clock Select). Defines the clock mode for timer/counter 1 where:
Bits
210
Description
0 0 0: No Clock (Counter 1 stopped)
0 0 1: Prescaled system clock
0 1 0: External Event on TBn
0 1 1: Pulse Accumulate
1 0 0: Slow-speed Clock
Other: Reserved
Revision 1.07
143
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