MC68HC908AB32 MOTOROLA [Motorola, Inc], MC68HC908AB32 Datasheet - Page 186

• Manufacturer Part Number: MC68HC908AB32
• Description: HCMOS Microcontroller Unit
• Manufacturer: MOTOROLA [Motorola, Inc]

Timer Interface Module A (TIMA)
11.10.2 TIMA Counter Registers
Technical Data
186
NOTE:
Address:
PS[2:0] — Prescaler Select Bits
The two read-only TIMA counter registers contain the high and low bytes
of the value in the TIMA counter. Reading the high byte (TACNTH)
latches the contents of the low byte (TACNTL) into a buffer. Subsequent
reads of TACNTH do not affect the latched TACNTL value until TACNTL
is read. Reset clears the TIMA counter registers. Setting the TIMA reset
bit (TRST) also clears the TIMA counter registers.
If you read TACNTH during a break interrupt, be sure to unlatch
TACNTL by reading TACNTL before exiting the break interrupt.
Otherwise, TACNTL retains the value latched during the break.
Reset:
Read:
Write:
PS2
These read/write bits select either the PTD6/TACLK pin or one of the
seven prescaler outputs as the input to the TIMA counter as
Table 11-2
Freescale Semiconductor, Inc.
0
0
0
0
1
1
1
1
For More Information On This Product,
Figure 11-5. TIMA Counter Register High (TACNTH)
$0022
Bit 15
Bit 7
0
Timer Interface Module A (TIMA)
PS1
0
0
1
1
0
0
1
1
Go to: www.freescale.com
shows. Reset clears the PS[2:0] bits.
= Unimplemented
14
6
0
PS0
Table 11-2. Prescaler Selection
0
1
0
1
0
1
0
1
13
5
0
12
4
0
Internal Bus Clock 1
Internal Bus Clock
Internal Bus Clock
Internal Bus Clock
Internal Bus Clock
Internal Bus Clock
Internal Bus Clock
TIM Clock Source
11
PTD6/TACLK
3
0
MC68HC908AB32
10
2
0
2
4
8
16
32
64
1
9
0
MOTOROLA
—
Rev. 1.0
Bit 0
Bit 8
0