Datasheet

I/O Registers
MC68HC908AZ60A • MC68HC908AS60A • MC68HC908AS60E Data Sheet, Rev. 6
Freescale Semiconductor 319
25.8.3 TIMA Counter Modulo Registers
The read/write TIMA modulo registers contain the modulo value for the
TIMA counter. When the TIMA counter reaches the modulo value, the
overflow flag (TOF) becomes set and the TIMA counter resumes counting
from $0000 at the next timer clock. Writing to the high byte (TAMODH)
inhibits the TOF bit and overflow interrupts until the low byte (TAMODL) is
written. Reset sets the TIMA counter modulo registers.
NOTE
Reset the TIMA counter before writing to the TIMA counter modulo registers.
Register Name and Address TACNTH — $0022
Bit 7654321Bit 0
Read: BIT 15 BIT 14 BIT 13 BIT 12 BIT 11 BIT 10 BIT 9 BIT 8
Write:
Reset:00000000
Register Name and Address TACNTL — $0023
Bit 7654321Bit 0
Read: BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0
Write:
Reset:00000000
= Unimplemented
Figure 25-5. TIMA Counter Registers (TACNTH and TACNTL)
Register Name and Address TAMODH — $0024
Bit 7654321Bit 0
Read:
BIT 15 BIT 14 BIT 13 BIT 12 BIT 11 BIT 10 BIT 9 BIT 8
Write:
Reset:11111111
Register Name and Address TAMODL — $0025
Bit 7654321Bit 0
Read:
BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0
Write:
Reset:11111111
Figure 25-6. TIMA Counter Modulo Registers (TAMODH and TAMODL)