參數(shù)資料
型號: MC68HC05P9AVP
廠商: 飛思卡爾半導體(中國)有限公司
英文描述: HCMOS Microcontroller Unit
中文描述: HCMOS微控制器
文件頁數(shù): 98/158頁
文件大小: 1106K
代理商: MC68HC05P9AVP
Timer
98
Timer
MOTOROLA
Timer Registers
The read-only timer registers (TRH and TRL) contain the current high
and low bytes of the 16-bit counter. Reading TRH before reading TRL
causes TRL to be latched until TRL is read. Reading TRL after reading
the timer status register clears the timer overflow flag (TOF). Writing to
the timer registers has no effect.
Reading TRH returns the current value of the high byte of the counter
and causes the low byte to be latched into a buffer. The buffer value
remains fixed even if the high byte is read more than once. Reading TRL
reads the transparent low byte buffer and completes the read sequence
of the timer registers.
Figure 54. Timer Register Reads
NOTE:
To prevent interrupts from occurring between readings of TRH and TRL,
set the interrupt mask (I bit) in the condition code register before reading
TRH, and clear the mask after reading TRL.
$0018
Bit 7
6
5
4
3
2
1
Bit 0
Read:
Bit 15
14
13
12
11
10
9
Bit 8
Write:
Reset:
Reset initializes TRH to $FF
$0019
Bit 7
6
5
4
3
2
1
Bit 0
Read:
Bit 7
6
5
4
3
2
1
Bit 0
Write:
Reset:
Reset initializes TRL to $FC
= Unimplemented
Figure 53. Timer Registers (TRH and TRL)
TRH ($0018)
TRL ($0019)
BUFFER
INTERNAL
DATA BUS
READ TRH
LATCH
18-tim1ic1oc_a
F
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
.
相關PDF資料
PDF描述
MC68HC05P9ACP HCMOS Microcontroller Unit
MC68HC05P9ADW HCMOS Microcontroller Unit
MC68HC05P9AMDW HCMOS Microcontroller Unit
MC68HC05P9AMP HCMOS Microcontroller Unit
MC68HC05P9AP HCMOS Microcontroller Unit
相關代理商/技術參數(shù)
參數(shù)描述
MC68HC05P9DW 制造商:FREESCALE 制造商全稱:Freescale Semiconductor, Inc 功能描述:HCMOS MICROCONTROLLER UNIT
MC68HC05P9P 制造商:FREESCALE 制造商全稱:Freescale Semiconductor, Inc 功能描述:HCMOS MICROCONTROLLER UNIT
MC68HC05PV8 制造商:FREESCALE 制造商全稱:Freescale Semiconductor, Inc 功能描述:Techinal Data - rev 1.9
MC68HC05PV8A 制造商:FREESCALE 制造商全稱:Freescale Semiconductor, Inc 功能描述:Techinal Data - rev 1.9
MC68HC05RC16 制造商:FREESCALE 制造商全稱:Freescale Semiconductor, Inc 功能描述:General Release Specification