- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄201872 > MC68HSC05C8AP (FREESCALE SEMICONDUCTOR INC) 8-BIT, MROM, 4.1 MHz, MICROCONTROLLER, PDIP40 PDF資料下載
參數(shù)資料
| 型號： | MC68HSC05C8AP |
| 廠商： | FREESCALE SEMICONDUCTOR INC |
| 元件分類： | 微控制器/微處理器 |
| 英文描述： | 8-BIT, MROM, 4.1 MHz, MICROCONTROLLER, PDIP40 |
| 封裝： | PLASTIC, DIP-40 |
| 文件頁數(shù)： | 53/116頁 |
| 文件大小： | 781K |
| 代理商： | MC68HSC05C8AP |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁第52頁當前第53頁第54頁第55頁第56頁第57頁第58頁第59頁第60頁第61頁第62頁第63頁第64頁第65頁第66頁第67頁第68頁第69頁第70頁第71頁第72頁第73頁第74頁第75頁第76頁第77頁第78頁第79頁第80頁第81頁第82頁第83頁第84頁第85頁第86頁第87頁第88頁第89頁第90頁第91頁第92頁第93頁第94頁第95頁第96頁第97頁第98頁第99頁第100頁第101頁第102頁第103頁第104頁第105頁第106頁第107頁第108頁第109頁第110頁第111頁第112頁第113頁第114頁第115頁第116頁
MC68HC05C8A MC68HCL05C8A MC68HSC05C8A Data Sheet, Rev. 5.1
Freescale Semiconductor
41
Chapter 8
Timer
8.1 Introduction
The timer consists of a 16-bit, software-programmable counter driven by a fixed divide-by-four prescaler.
This timer can be used for many purposes, including input waveform measurements while simultaneously
generating an output waveform. Pulse widths can vary from several microseconds to many seconds.
Refer to Figure 8-1 for a timer block diagram.
Because the timer has a 16-bit architecture, each specific functional segment (capability) is represented
by two registers. These registers contain the high and low byte of that functional segment. Generally,
accessing the low byte of a specific timer function allows full control of that function; however, an access
of the high byte inhibits that specific timer function until the low byte is also accessed.
NOTE
The I bit in the condition code register should be set while manipulating both
the high and low byte register of a specific timer function to ensure that an
interrupt does not occur.
8.2 Counter
The key element in the programmable timer is a 16-bit, free-running counter or counter register, preceded
by a prescaler that divides the internal processor clock by four. The prescaler gives the timer a resolution
of 2.0 microseconds if the internal bus clock is 2.0 MHz. The counter is incremented during the low portion
of the internal bus clock. Software can read the counter at any time without affecting its value.
The double-byte, free-running counter can be read from either of two locations, $18, $19 (counter register)
or $1A, $1B (counter alternate register). A read from only the least significant byte (LSB) of the
free-running counter ($19, $1B) receives the count value at the time of the read. If a read of the
free-running counter or counter alternate register first addresses the most significant byte (MSB) ($18,
$1A), the LSB ($19, $1B) is transferred to a buffer. This buffer value remains fixed after the first MSB read,
even if the user reads the MSB several times. This buffer is accessed when reading the free-running
counter or counter alternate register LSB ($19 or $1B) and, thus, completes a read sequence of the total
counter value. In reading either the free-running counter or counter alternate register, if the MSB is read,
the LSB must also be read to complete the sequence.
The counter alternate register differs from the counter register in one respect: A read of the counter
register MSB can clear the timer overflow flag (TOF). Therefore, the counter alternate register can be read
at any time without the possibility of missing timer overflow interrupts due to clearing of the TOF.
相關PDF資料 |
PDF描述 |
|---|---|
| MC9S12KG64CPV | 16-BIT, FLASH, 25 MHz, MICROCONTROLLER, PQFP112 |
| MC9S12KG64VPV | 16-BIT, FLASH, 25 MHz, MICROCONTROLLER, PQFP112 |
| MAC7122MPV50 | 32-BIT, FLASH, 50 MHz, MICROCONTROLLER, PQFP112 |
| M38039FFHWG | 8-BIT, FLASH, 8.4 MHz, MICROCONTROLLER, PBGA64 |
| MPC740ARX200TX | 32-BIT, 200 MHz, RISC PROCESSOR, CBGA255 |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| MC68HSC705C8ACFB | 制造商:Rochester Electronics LLC 功能描述:8 BIT MCU, 304 BYTES RAM - Bulk |
| MC68HSC705C8ACP | 制造商:Rochester Electronics LLC 功能描述: 制造商:Freescale Semiconductor 功能描述: |
| MC68HSC705C8ACS | 制造商:Rochester Electronics LLC 功能描述:- Bulk |
| MC68HSC705J1ACDW | 制造商:Rochester Electronics LLC 功能描述:- Bulk |
| MC68HSC705J1ACP | 制造商:Rochester Electronics LLC 功能描述:8 BIT MCU, 64 BYTES RAM - Bulk |
發(fā)布緊急采購，3分鐘左右您將得到回復。