s908qc16vdse Freescale Semiconductor, Inc, s908qc16vdse Datasheet - Page 214

• Manufacturer Part Number: s908qc16vdse
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Timer Interface Module (TIM2)
PS[2:0] — Prescaler Select Bits
17.8.2 TIM2 Counter Registers
The two read-only TIM2 counter registers contain the high and low bytes of the value in the counter.
Reading the high byte (T2CNTH) latches the contents of the low byte (T2CNTL) into a buffer. Subsequent
reads of T2CNTH do not affect the latched T2CNTL value until T2CNTL is read. Reset clears the TIM2
counter registers. Setting the TIM2 reset bit (TRST) also clears the TIM2 counter registers.
214
These read/write bits select one of the seven prescaler outputs as the input to the counter as
Table 17-1
Reset:
Reset:
shows.
Read:
Write:
Read:
Write:
If you read T2CNTH during a break interrupt, be sure to unlatch T2CNTL
by reading T2CNTL before exiting the break interrupt. Otherwise, T2CNTL
retains the value latched during the break.
MC68HC908QC16 • MC68HC908QC8 • MC68HC908QC4 Data Sheet, Rev. 4
Bit 15
Bit 7
Bit 7
Bit 7
0
0
Figure 17-5. TIM2 Counter High Register (T2CNTH)
PS2
Figure 17-6. TIM2 Counter Low Register (T2CNTL)
0
0
0
0
1
1
1
1
= Unimplemented
Bit 14
Bit 6
6
0
6
0
PS1
Table 17-1. Prescaler Selection
0
0
1
1
0
0
1
1
Bit 13
Bit 5
5
0
5
0
PS0
0
1
0
1
0
1
0
1
Bit 12
NOTE
Bit 4
4
0
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
TIM2 Clock Source
Bit 11
T2CLK (if available)
Bit 3
3
0
3
0
Bit 10
Bit 2
2
0
2
0
Bit 9
Bit 1
1
0
1
0
Freescale Semiconductor
Bit 0
Bit 8
Bit 0
Bit 0
0
0