MC68HC908GR8CD Freescale Semiconductor, MC68HC908GR8CD Datasheet - Page 227

• Manufacturer Part Number: MC68HC908GR8CD
• Description: 8-bit Microcontrollers - MCU 8 Bit 8MHz
• Manufacturer: Freescale Semiconductor

Specifications of MC68HC908GR8CD

• Product Category: 8-bit Microcontrollers - MCU
• Rohs: yes
• Core: HC08
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 8 MHz
• Program Memory Size: 64 KB
• Data Ram Size: 384 B
• Operating Supply Voltage: 3 V to 5 V
• Package / Case: SOIC-28
• Mounting Style: SMD/SMT
• Data Rom Size: 64 KB
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Number Of Programmable I/os: 21
• Program Memory Type: Flash

If the timebase functions are not required during stop mode, reduce the power consumption by stopping
the timebase before enabling the STOP instruction.
21.6 Timebase Register Description
The timebase has one register, the TBCR, which is used to enable the timebase interrupts and set the
rate.
TBIF — Timebase Interrupt Flag
TBR2:TBR0 — Timebase Rate Selection
TACK— Timebase ACKnowledge
Freescale Semiconductor
This read-only flag bit is set when the timebase counter has rolled over.
These read/write bits are used to select the rate of timebase interrupts as shown in
The TACK bit is a write-only bit and always reads as 0. Writing a 1 to this bit clears TBIF, the timebase
interrupt flag bit. Writing a 0 to this bit has no effect.
1 = Timebase interrupt pending
0 = Timebase interrupt not pending
1 = Clear timebase interrupt flag
0 = No effect
Address:
Do not change TBR2–TBR0 bits while the timebase is enabled (TBON = 1).
Reset:
TBR2
Read:
Write:
0
0
0
0
1
1
1
1
Table 21-1. Timebase Rate Selection for OSC1 = 32.768 kHz
$001C
TBIF
Bit 7
0
TBR1
Figure 21-2. Timebase Control Register (TBCR)
0
0
1
1
0
0
1
1
MC68HC908GR8 • MC68HC908GR4 Data Sheet, Rev. 7
= Unimplemented
TBR2
6
0
TBR0
0
1
0
1
0
1
0
1
TBR1
5
0
Divider
32,768
8192
2048
NOTE
128
64
32
16
TBR0
8
R
4
0
= Reserved
TACK
3
0
0
1024
2048
4096
Timebase Interrupt Rate
256
512
Hz
16
1
4
TBIE
2
0
Timebase Register Description
TBON
1
0
~0.24
1000
~ 3.9
62.5
~0.5
250
ms
~2
~1
Bit 0
Table
R
0
21-1.
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