mc68hc05pv8a Freescale Semiconductor, Inc, mc68hc05pv8a Datasheet - Page 119

• Manufacturer Part Number: mc68hc05pv8a
• Description: Mc68hc05pv8a Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

8.3 Registers
8.3.1 Core Timer Status & Control Register (CTSCR)
MC68HC(8)05PV8/A — Rev. 1.9
The CTSCR contains the timer interrupt flag, the timer interrupt enable
bits, and the real time interrupt rate select bits.
value of each bit in the CTSCR when coming out of reset.
TOF – Timer Over Flow
RTIF – Real Time Interrupt Flag
TOFE – Timer Over Flow Enable
RTIE – Real Time Interrupt Enable
Reset:
$0008
Read:
Write:
Figure 8-2 Core Timer Status and Control Register (CTSCR)
TOF is a read-only status bit and is set when the 8-bit ripple counter
rolls over from $FF to $00. A CPU interrupt request will be generated
if TOFE is set. Reset clears TOF.
The real time interrupt circuit consists of a three stage divider and a 1
of 4 selector. The clock frequency that drives the RTI circuit is f
(or f
interrupt period of about 250ms at a crystal frequency of 1 MHz. RTIF
is a read-only status bit and is set when the output of the chosen (1 of
4 selection) stage goes active. A CPU interrupt request will be
generated if RTIE is set. Reset clears RTIF.
When this bit is set, a CPU interrupt request is generated when the
TOF bit is set. Reset clears this bit.
When this bit is set, a CPU interrupt request is generated when the
RTIF bit is set. Reset clears this bit.
Freescale Semiconductor, Inc.
For More Information On This Product,
op
Bit 7
TOF
/8192) with three additional divider stages giving a maximum
0
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RTIF
6
0
Core Timer
TOFE
5
0
RTIE
4
0
RTOF
3
0
0
Figure 8-2
RRTIF
2
0
0
RT1
shows the
1
1
Technical Data
Core Timer
Registers
op
Bit 0
RT0
1
/2
13