MC68HC908GT16_07 FREESCALE [Freescale Semiconductor, Inc], MC68HC908GT16_07 Datasheet - Page 232

• Manufacturer Part Number: MC68HC908GT16_07
• Description: Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Timer Interface Module (TIM)
PS[2:0] — Prescaler Select Bits
18.9.2 TIM Counter Registers
The two read-only TIM counter registers contain the high and low bytes of the value in the TIM counter.
Reading the high byte (TCNTH) latches the contents of the low byte (TCNTL) into a buffer. Subsequent
reads of TCNTH do not affect the latched TCNTL value until TCNTL is read. Reset clears the TIM counter
registers. Setting the TIM reset bit (TRST) also clears the TIM counter registers.
232
These read/write bits select one of the seven prescaler outputs as the input to the TIM counter as
18-1
shows. Reset clears the PS[2:0] bits.
Address: T1CNTH, $0021 and T2CNTH, $002C
Address: T1CNTL, $0022 and T2CNTL, $002D
If you read TCNTH during a break interrupt, be sure to unlatch TCNTL by
reading TCNTL before exiting the break interrupt. Otherwise, TCNTL
retains the value latched during the break.
Reset:
Reset:
Read:
Read:
Write:
Write:
MC68HC908GT16 • MC68HC908GT8 • MC68HC08GT16 Data Sheet, Rev. 5.0
PS2
Bit 15
0
0
0
0
1
1
1
1
Bit 7
Bit 7
Bit 7
0
0
Figure 18-6. TIM Counter Registers High (TCNTH)
Figure 18-7. TIM Counter Registers Low (TCNTL)
= Unimplemented
= Unimplemented
14
PS1
6
0
6
6
0
0
0
1
1
0
0
1
1
Table 18-1. Prescaler Selection
13
5
0
5
5
0
PS0
0
1
0
1
0
1
0
1
NOTE
12
4
0
4
4
0
Internal bus clock ÷ 16
Internal bus clock ÷ 32
Internal bus clock ÷ 64
Internal bus clock ÷ 1
Internal bus clock ÷ 2
Internal bus clock ÷ 4
Internal bus clock ÷ 8
11
3
0
3
3
0
TIM Clock Source
Not available
10
2
0
2
2
0
1
9
0
1
1
0
Freescale Semiconductor
Bit 0
Bit 8
Bit 0
Bit 0
0
0
Table