- 您现在的位置：买卖IC网 > PDF目录367738 > P83C654IBBB (NXP SEMICONDUCTORS) CMOS single-chip 8-bit microcontroller PDF资料下载
参数资料
| 型号： | P83C654IBBB |
| 厂商： | NXP SEMICONDUCTORS |
| 元件分类： | 微控制器/微处理器 |
| 英文描述： | CMOS single-chip 8-bit microcontroller |
| 中文描述： | 8-BIT, MROM, 24 MHz, MICROCONTROLLER, PQFP44 |
| 封装： | 10 X 10 X 1.75 MM, PLASTIC, QFP-44 |
| 文件页数： | 13/88页 |
| 文件大小： | 497K |
| 代理商： | P83C654IBBB |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页当前第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页第41页第42页第43页第44页第45页第46页第47页第48页第49页第50页第51页第52页第53页第54页第55页第56页第57页第58页第59页第60页第61页第62页第63页第64页第65页第66页第67页第68页第69页第70页第71页第72页第73页第74页第75页第76页第77页第78页第79页第80页第81页第82页第83页第84页第85页第86页第87页第88页
Philips Semiconductors
Product data
P83C654X2/P87C654X2
80C51 8-bit microcontroller family
16 kB OTP/ROM,
256B RAM, low voltage (2.7 to 5.5 V), low power, high speed
(30/33 MHz)
2004 Apr 20
13
TIMER 0 AND TIMER 1 OPERATION
Timer 0 and Timer 1
The “Timer” or “Counter” function is selected by control bits C/T in
the Special Function Register TMOD. These two Timer/Counters
have four operating modes, which are selected by bit-pairs (M1, M0)
in TMOD. Modes 0, 1, and 2 are the same for both Timers/Counters.
Mode 3 is different. The four operating modes are described in the
following text.
Mode 0
Putting either Timer into Mode 0 makes it look like an 8048 Timer,
which is an 8-bit Counter with a divide-by-32 prescaler. Figure 3
shows the Mode 0 operation.
In this mode, the Timer register is configured as a 13-bit register. As
the count rolls over from all 1s to all 0s, it sets the Timer interrupt
flag TFn. The counted input is enabled to the Timer when TRn = 1
and either GATE = 0 or INTn = 1. (Setting GATE = 1 allows the
Timer to be controlled by external input INTn, to facilitate pulse width
measurements). TRn is a control bit in the Special Function Register
TCON (Figure 4).
The 13-bit register consists of all 8 bits of THn and the lower 5 bits
of TLn. The upper 3 bits of TLn are indeterminate and should be
ignored. Setting the run flag (TRn) does not clear the registers.
Mode 0 operation is the same for Timer 0 as for Timer 1. There are
two different GATE bits, one for Timer 1 (TMOD.7) and one for Timer
0 (TMOD.3).
Mode 1
Mode 1 is the same as Mode 0, except that the Timer register is
being run with all 16 bits.
Mode 2
Mode 2 configures the Timer register as an 8-bit Counter (TLn) with
automatic reload, as shown in Figure 5. Overflow from TLn not only
sets TFn, but also reloads TLn with the contents of THn, which is
preset by software. The reload leaves THn unchanged.
Mode 2 operation is the same for Timer 0 as for Timer 1.
Mode 3
Timer 1 in Mode 3 simply holds its count. The effect is the same as
setting TR1 = 0.
Timer 0 in Mode 3 establishes TL0 and TH0 as two separate
counters. The logic for Mode 3 on Timer 0 is shown in Figure 6. TL0
uses the Timer 0 control bits: C/T, GATE, TR0, and TF0 as well as
pin INT0. TH0 is locked into a timer function (counting machine
cycles) and takes over the use of TR1 and TF1 from Timer 1. Thus,
TH0 now controls the “Timer 1” interrupt.
Mode 3 is provided for applications requiring an extra 8-bit timer on
the counter. With Timer 0 in Mode 3, an 80C51 can look like it has
three Timer/Counters. When Timer 0 is in Mode 3, Timer 1 can be
turned on and off by switching it out of and into its own Mode 3, or
can still be used by the serial port as a baud rate generator, or in
fact, in any application not requiring an interrupt.
GATE
C/T
M1
M0
GATE
C/T
M1
M0
BIT
TMOD.3/
TMOD.7
TMOD.2/
TMOD.6
SYMBOL
GATE
FUNCTION
Gating control when set. Timer/Counter “n” is enabled only while “INTn” pin is high and
“TRn” control pin is set. when cleared Timer “n” is enabled whenever “TRn” control bit is set.
Timer or Counter Selector cleared for Timer operation (input from internal system clock.)
Set for Counter operation (input from “Tn” input pin).
C/T
M1
M0
OPERATING
0
0
8048 Timer: “TLn” serves as 5-bit prescaler.
0
1
16-bit Timer/Counter: “THn” and “TLn” are cascaded; there is no prescaler.
1
0
8-bit auto-reload Timer/Counter: “THn” holds a value which is to be reloaded
into “TLn” each time it overflows.
1
1
(Timer 0) TL0 is an 8-bit Timer/Counter controlled by the standard Timer 0 control bits.
TH0 is an 8-bit timer only controlled by Timer 1 control bits.
1
1
(Timer 1) Timer/Counter 1 stopped.
SU01580
TIMER 1
TIMER 0
Not Bit Addressable
TMOD
Address = 89H
Reset Value = 00H
7
6
5
4
3
2
1
0
Figure 2. Timer/Counter 0/1 Mode Control (TMOD) Register
相关PDF资料 |
PDF描述 |
|---|---|
| P83C654IFAA | CMOS single-chip 8-bit microcontroller |
| P83C654IFB | CMOS single-chip 8-bit microcontroller |
| P83C654IFBB | LAN Tester |
| P83C654IFP | CMOS single-chip 8-bit microcontroller |
| P83C654IFPN | CMOS single-chip 8-bit microcontroller |
相关代理商/技术参数 |
参数描述 |
|---|---|
| P83C654IBP | 制造商:PHILIPS 制造商全称:NXP Semiconductors 功能描述:CMOS single-chip 8-bit microcontroller |
| P83C654IBPN | 制造商:PHILIPS 制造商全称:NXP Semiconductors 功能描述:CMOS single-chip 8-bit microcontroller |
| P83C654IFA | 制造商:PHILIPS 制造商全称:NXP Semiconductors 功能描述:CMOS single-chip 8-bit microcontroller |
| P83C654IFAA | 制造商:PHILIPS 制造商全称:NXP Semiconductors 功能描述:CMOS single-chip 8-bit microcontroller |
| P83C654IFB | 制造商:PHILIPS 制造商全称:NXP Semiconductors 功能描述:CMOS single-chip 8-bit microcontroller |
发布紧急采购，3分钟左右您将得到回复。