- 您现在的位置：买卖IC网 > PDF目录367728 > P83C576EBAA (NXP SEMICONDUCTORS) 80C51 8-bit microcontroller family 8K/256 OTP/ROM, 6 channel 10-bit A/D, 4 comparators, failure detect circuitry, watchdog timer PDF资料下载
参数资料
| 型号： | P83C576EBAA |
| 厂商： | NXP SEMICONDUCTORS |
| 元件分类： | 微控制器/微处理器 |
| 英文描述： | 80C51 8-bit microcontroller family 8K/256 OTP/ROM, 6 channel 10-bit A/D, 4 comparators, failure detect circuitry, watchdog timer |
| 中文描述： | 8-BIT, MROM, 16 MHz, MICROCONTROLLER, PQCC44 |
| 封装： | PLASTIC, MO-047AC, SOT-187-2, LCC-44 |
| 文件页数： | 18/46页 |
| 文件大小： | 447K |
| 代理商： | P83C576EBAA |
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页第13页第14页第15页第16页第17页当前第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
Philips Semiconductors
Product specification
83C576/87C576
80C51 8-bit microcontroller family
8K/256 OTP/ROM, 6 channel 10-bit A/D, 4 comparators,
failure detect circuitry, watchdog timer
1998 Jun 04
18
The tap selection is programmable. The watchdog main counter is a
down counter clocked (decremented) each time the programmable
prescaler overflows. The watchdog generates an underflow signal
(and is autoloaded) when the watchdog is at count 0 and the prescaler
clock decrements the watchdog. The watchdog is 8 bits long and the
autoload value can range from 0 to FFH. (The autoload value of 0 is
permissible since the prescaler is cleared upon autoload).
This leads to the following user design equations. Definitions :t
OSC
is the oscillator period, N is the selected prescaler tap value, W is
the main counter autoload value, t
MIN
is the minimum watchdog
time-out value (when the autoload value is 0), t
MAX
is the maximum
time-out value (when the autoload value is FFH), t
D
is the design
time-out value.
t
MIN
= t
OSC
×
2
×
64
t
MAX
= t
MIN
×
128
×
256
t
D
= t
MIN
×
2
PRESCALER
×
(W + 1)
(where prescaler = 0, 1, 2, 3, 4, 5, 6, or 7)
Note that the design procedure is anticipated to be as follows. A
t
MAX
will be chosen either from equipment or operation
considerations and will most likely be the next convenient value
higher than t
D
. (If the watchdog were inadvertently to start from 00H,
an underflow would be guaranteed, barring other anomalies, to
occur within t
MAX
).
The software must be written so that a feed operation takes place
every t
D
seconds from the last feed operation. Some tradeoffs may
need to be made. It is not advisable to include feed operations in
minor loops or in subroutines unless the feed operation is a specific
subroutine.
Watchdog Control Register (WDCON)
Address C4H
The following bits of this register are read only in the ROM part
when EA is high: WDMOD, DPD, OFRE, LVRE, PRE0, PRE1, and
PRE2. That is, the register will reflect the mask programmed values.
In the ROM part with EA high, these bits are taken from mask coded
bits and are not readable by the program. WDRUN is read only in
the ROM part when EA is high and WDMOD is in the watchdog
mode. When WDMOD is in the timer mode, WDRUN functions
normally.
The parameters written into WDMOD, DPD, OFRE, LVRE, PRE0,
PRE1, and PRE2 by the program are not applied directly to the
watchdog timer subsystem. The watchdog timer subsystem is
directly controlled by a second register which stores these bits. The
transfer of these bits from the user register to the second control
register takes place when the watchdog is fed. This prevents
random code execution from directly foiling the watchdog function.
This does not affect the operation where these bits are taken from
mask coded values.
The reset values of the WDCON and WDL registers will be such that
the timer resets to the watchdog mode with a timeout period of 2
×
64
×
128
×
t
OSC
. The watchdog timer does not generate an interrupt.
Additional bits in WDCON are used to disable reset generation by
the oscillator fail and low voltage detect circuits. WDCON can be
written by software only by executing a valid watchdog feed
sequence.
WDCON Register Bit Definitions
WDCON.7
PRE2
WDCON.6
PRE1
WDCON.5
PRE0
WDCON.4
LVRE
Prescaler Select 2, reset to 1
Prescaler Select 1, reset to 1
Prescaler Select 0, reset to 1
Low Voltage Reset Enable, reset to 1
(enabled)
Oscillator Fail Reset Enable, reset to 1
(enabled)
Disable Power Down
Watchdog Run, reset to 1 (enabled)
Watchdog Mode, reset to 1 (watchdog
mode)
WDCON.3
OFRE
WDCON.2
WDCON.1
WDCON.0
DPD
WDRUN
WDMOD
Enhanced UART
The UART operates in all of the usual modes that are described in
the first section of this book for the 80C51. In addition the UART can
perform framing error detect by looking for missing stop bits, and
automatic address recognition. The 8XC576 UART also fully
supports multiprocessor communication as does the standard
80C51 UART.
When used for framing error detect the UART looks for missing stop
bits in the communication. A missing bit will set the FE bit in the
SCON register. The FE bit shares the SCON.7 bit with SM0 and the
function of SCON.7 is determined by PCON.6 (SMOD0) (see Figure
20). If SMOD0 is set then SCON.7 functions as FE. SCON.7
functions as SM0 when SMOD0 is cleared. When used as FE
SCON.7 can only be cleared by software. Refer to Figure 19.
The serial port transmitter data can be inverted by setting the TXI
(AUXR.2) bit. For normal operation, the TXI bit should be cleared.
Automatic Address Recognition
Automatic Address Recognition is a feature which allows the UART
to recognize certain addresses in the serial bit stream by using
hardware to make the comparisons. This feature saves a great deal
of software overhead by eliminating the need for the software to
examine every serial address which passes by the serial port. This
feature is enabled by setting the SM2 bit in SCON. In the 9 bit UART
modes, mode 2 and mode 3, the Receive Interrupt flag (RI) will be
automatically set when the received byte contains either the “Given”
address or the “Broadcast” address. The 9 bit mode requires that
the 9th information bit is a 1 to indicate that the received information
is an address and not data. Automatic address recognition is shown
in Figure 21.
The 8 bit mode is called Mode 1. In this mode the RI flag will be set
if SM2 is enabled and the information received has a valid stop bit
following the 8 address bits and the information is either a Given or
Broadcast address.
Mode 0 is the Shift Register mode and SM2 is ignored.
相关PDF资料 |
PDF描述 |
|---|---|
| P83C576EHPN | 80C51 8-bit microcontroller family 8K/256 OTP/ROM, 6 channel 10-bit A/D, 4 comparators, failure detect circuitry, watchdog timer |
| P87C576EHPN | 80C51 8-bit microcontroller family 8K/256 OTP/ROM, 6 channel 10-bit A/D, 4 comparators, failure detect circuitry, watchdog timer |
| P83C576EBBB | 80C51 8-bit microcontroller family 8K/256 OTP/ROM, 6 channel 10-bit A/D, 4 comparators, failure detect circuitry, watchdog timer |
| P87C576EBBB | 80C51 8-bit microcontroller family 8K/256 OTP/ROM, 6 channel 10-bit A/D, 4 comparators, failure detect circuitry, watchdog timer |
| P87C576EBAA | 80C51 8-bit microcontroller family 8K/256 OTP/ROM, 6 channel 10-bit A/D, 4 comparators, failure detect circuitry, watchdog timer |
相关代理商/技术参数 |
参数描述 |
|---|---|
| P83C576EBB | 制造商:未知厂家 制造商全称:未知厂家 功能描述:8-Bit Microcontroller |
| P83C576EBBB | 制造商:PHILIPS 制造商全称:NXP Semiconductors 功能描述:80C51 8-bit microcontroller family 8K/256 OTP/ROM, 6 channel 10-bit A/D, 4 comparators, failure detect circuitry, watchdog timer |
| P83C576EBN | 制造商:未知厂家 制造商全称:未知厂家 功能描述:Microcontroller |
| P83C576EBP | 制造商:未知厂家 制造商全称:未知厂家 功能描述:8-Bit Microcontroller |
| P83C576EBPN | 制造商:PHILIPS 制造商全称:NXP Semiconductors 功能描述:80C51 8-bit microcontroller family 8K/256 OTP/ROM, 6 channel 10-bit A/D, 4 comparators, failure detect circuitry, watchdog timer |
发布紧急采购，3分钟左右您将得到回复。