MC68HLC908QY4 Datasheet, PDF (129/182 Pages) Motorola, Inc – Microcontrollers

Input/Output Registers
Address: $0021 TCNTH
Bit 7
6
5
4
3
2
1
Bit 0
Read: Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
Write:
Reset: 0
0
0
0
0
0
0
0
Address: $0022 TCNTL
Bit 7
6
5
4
3
2
1
Bit 0
Read: Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Write:
Reset: 0
0
0
0
0
0
0
0
= Unimplemented
Figure 14-5. TIM Counter Registers (TCNTH:TCNTL)
14.9.3 TIM Counter Modulo Registers
The read/write TIM modulo registers contain the modulo value for the TIM counter. When the TIM counter
reaches the modulo value, the overflow flag (TOF) becomes set, and the TIM counter resumes counting
from $0000 at the next timer clock. Writing to the high byte (TMODH) inhibits the TOF bit and overflow
interrupts until the low byte (TMODL) is written. Reset sets the TIM counter modulo registers.
Address: $0023 TMODH
Bit 7
6
5
4
3
2
1
Bit 0
Read:
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
Write:
Reset: 1
1
1
1
1
1
1
1
Address: $0024 TMODL
Bit 7
6
5
4
3
2
1
Bit 0
Read:
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Write:
Reset: 1
1
1
1
1
1
1
1
Figure 14-6. TIM Counter Modulo Registers (TMODH:TMODL)
NOTE
Reset the TIM counter before writing to the TIM counter modulo registers.
MC68HLC908QY/QT Family Data Sheet, Rev. 3
Freescale Semiconductor
129