參數(shù)資料
型號(hào)： SAA5647HL
廠商： NXP Semiconductors N.V.
英文描述： Enhanced TV microcontrollers with On-Screen Display (OSD)(帶全屏顯示的增強(qiáng)型TV控制器)
中文描述： 與微控制器在強(qiáng)化電視屏幕顯示（OSD）（帶全屏顯示的增強(qiáng)型電視控制器）
文件頁(yè)數(shù)： 47/112頁(yè)
文件大小： 436K
代理商： SAA5647HL
2000 Jun 30
47
Philips Semiconductors
Objective specification
Enhanced TV microcontrollers with
On-Screen Display (OSD)
SAA56xx
18 UART PERIPHERAL
The 80C51 microcontroller incorporates a full duplex
UART with a single byte receive buffer, meaning that it can
commence reception of a second byte before the first is
read from the receive buffer. This register is implemented
twice. Writing to S0BUF writes to the transmit buffer.
Reading from S0BUF reads from the receive buffer. Only
hardware can read from the transmit buffer and write to the
receive buffer.
The UART’s TX and RX pins connect to P0.1 and P0.0,
respectively.
Two registers (S0CON, S0BUF) and one bit (SMOD in
PCON register) control the UART.
Table 19
UART Special Function Registers
18.1
UART modes
The serial port can operate in four modes:
Mode 0:
Serial data enters and exits through RX. TX
outputs the shift clock. Eight bits are transmitted and
received (LSB first). The baud rate is fixed at
1
6
f
clk
.
Mode 1:
Ten bits are transmitted (through TX) or
received(throughRX):astartbit(logic 0),eightdatabits
(LSB first) and a stop bit (logic 1). On receive, the stop
bit goes into RB8 in SFR S0CON. The baud rate can be
varied at either Timer 1 or Timer 2 overflow rate.
Mode 2:
Eleven bits are transmitted (through TX) or
received (through RX): start bit (logic 0), eight data bits
(LSB first), a 9
th
data bit and a stop bit (logic 1). On
transmit, the 9
th
data bit, TB8 in S0CON, can be
assigned thevalueoflogic 0or logic 1.For example,the
parity bit could be moved into TB8. On receive, the 9
th
data bit goes into RB8 in S0CON, while the stop bit is
ignored. The baud rate can be programmed to either
1
32
f
clk
or
1
64
f
clk
.
Mode 3:
Eleven bits are transmitted (through TX) or
received(throughRX):astartbit(logic 0),eightdatabits
(LSB first), a 9
th
data bit and a stop bit (logic 1). In fact,
mode 3 is the same as mode 2 in all respects except
baud rate. The baud rate can be varied at either Timer 1
or Timer 2 overflow rate.
In all four modes, transmission is initiated by any
instruction that uses S0BUF as a destination register.
ReceptionisinitiatedinMode 0bytheconditionRI = 0and
REN = 1. In the other modes, reception is initiated by the
incoming start bit if REN = 1.
18.2
UART multiprocessor communications
Modes 2 and 3 have a special provision for multiprocessor
communications. In these modes, nine data bits are
received. The 9
th
bit goes into RB8, followed by a stop bit.
The port can be programmed such that when the stop bit
is received, the serial port interrupt will be activated only if
RB8 = 1. This feature is enabled by setting bit SM2 in
S0CON. A way to use this feature in multiprocessor
systems is as follows.
When the master processor wants to transmit a block of
data to one of several slaves, it first sends out an address
byte which identifies the target slave. An address byte
differs from a data byte. The 9
th
bit is logic 1 in an address
byte and logic 0 in a data byte. With SM2 = 1, no slave will
be interrupted by a data byte reception.
An address byte, however, will interrupt all slaves, so that
each slave can examine the received byte and see if it is
being addressed. The addressed slave will clear its SM2
bit and prepare to receive the data bytes that will follow.
The slaves that were not being addressed leave their
SM2 bits set and carry on the task they were performing.
Bit SM2 has no effect in Mode 0; in Mode 1, it can be used
to check the validity of the stop bit. When receiving in
Mode 1 (if SM2 = 1), the receive interrupt will not be
activated unless a valid stop bit is received.
18.3
S0BUF registers
This register is implemented twice. Writing to S0BUF
writes to the transmit buffer. Reading from S0BUF reads
from the receive buffer. Only hardware can read from the
transmit buffer and write to the receive buffer.
SFR
ADDRESS
S0CON
S0BUF
99H
9AH
相關(guān)PDF資料
PDF描述
SAA5667HL Enhanced TV microcontrollers with On-Screen Display (OSD)(帶全屏顯示的增強(qiáng)型TV控制器)
SAA5697HL Enhanced TV microcontrollers with On-Screen Display (OSD)
SAA5675HL Enhanced TV microcontrollers with On-Screen Display (OSD)
SAA567X Enhanced TV microcontrollers with On-Screen Display (OSD)
SAA5695HL Enhanced TV microcontrollers with On-Screen Display (OSD)
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
SAA5665 制造商:PHILIPS 制造商全稱(chēng):NXP Semiconductors 功能描述:Enhanced TV microcontrollers with On-Screen Display OSD
SAA5665HL 制造商:PHILIPS 制造商全稱(chēng):NXP Semiconductors 功能描述:Enhanced TV microcontrollers with On-Screen Display OSD
SAA5667 制造商:PHILIPS 制造商全稱(chēng):NXP Semiconductors 功能描述:Enhanced TV microcontrollers with On-Screen Display OSD
SAA5667HL 制造商:PHILIPS 制造商全稱(chēng):NXP Semiconductors 功能描述:Enhanced TV microcontrollers with On-Screen Display OSD
SAA5675HL 制造商:PHILIPS 制造商全稱(chēng):NXP Semiconductors 功能描述:Enhanced TV microcontrollers with On-Screen Display (OSD)
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫(xiě)一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*