MC68HC705KJ1CDW Freescale Semiconductor, MC68HC705KJ1CDW Datasheet - Page 82

• Manufacturer Part Number: MC68HC705KJ1CDW
• Description: IC MCU 4MHZ 1.2K OTP 16-SOIC
• Manufacturer: Freescale Semiconductor
• Series: HC05r

Specifications of MC68HC705KJ1CDW

• Core Processor: HC05
• Core Size: 8-Bit
• Speed: 4MHz
• Peripherals: POR, WDT
• Number Of I /o: 10
• Program Memory Size: 1.2KB (1.2K x 8)
• Program Memory Type: OTP
• Ram Size: 64 x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 16-SOIC (0.300", 7.5mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Data Converters: -
• Connectivity: -

RT1 and RT0 — Real-Time Interrupt Select Bits
9.5.2 Timer Counter Register
A 15-stage ripple counter is the core of the timer. The value of the first eight stages is readable at any
time from the read-only timer counter register shown in
Power-on clears the entire counter chain and the internal clock begins clocking the counter. After 4064
cycles (or 16 cycles if the SOSCD bit in the mask option register is set), the power-on reset circuit is
released, clearing the counter again and allowing the MCU to come out of reset.
A timer overflow function at the eighth counter stage allows a timer interrupt every 1024 internal clock
cycles.
82
Multifunction Timer Module
These read/write bits select one of four real-time interrupt rates, as shown in
selected RTI output drives the COP watchdog, changing the real-time interrupt rate also changes the
counting rate of the COP watchdog. Reset sets RT1 and RT0.
RT1:RT0
Address:
Changing RT1 and RT0 when a COP timeout is imminent can cause a
real-time interrupt request to be missed or an additional real-time interrupt
request to be generated. To prevent this occurrence, clear the COP timer
before changing RT1 and RT0.
0 0
0 1
1 0
1 1
Reset:
Read:
Write:
MC68HC705KJ1 • MC68HRC705KJ1 • MC68HLC705KJ1 Data Sheet, Rev. 4.1
$0009
TCR7
Bit 7
f
RTI Rate
OP
f
f
f
0
OP
OP
OP
÷
÷
÷
Table 9-1. Real-Time Interrupt Rate Selection
÷
2
2
2
2
Figure 9-4. Timer Counter Register (TCR)
14
= Unimplemented
16
17
15
TCR6
6
0
(f
RTI Period
OP
16.4 ms
32.8 ms
65.5 ms
8.2 ms
= 2 MHz)
TCR5
5
0
NOTE
COP Timeout Period
TCR4
(–0/+1 RTI Period)
4
0
8 x RTI Period
8 x RTI Period
8 x RTI Period
8 x RTI Period
Figure
TCR3
3
0
9-4.
TCR2
2
0
Minimum COP Timeout
(f
OP
TCR1
131.1 ms
262.1 ms
524.3 ms
65.5 ms
Period
1
0
= 2 MHz)
Table
Freescale Semiconductor
TCR0
9-1. Because the
Bit 0
0