• <small id="zwrsh"><ul id="zwrsh"><ins id="zwrsh"></ins></ul></small>
    參數(shù)資料
    型號(hào)： P89C51X2
    廠商： NXP Semiconductors N.V.
    元件分類： 8位微控制器
    英文描述： 80C51 8-bit Flash microcontroller family
    中文描述： 80C51的8位閃存微控制器系列
    文件頁(yè)數(shù)： 21/68頁(yè)
    文件大?。?/td> 404K
    代理商： P89C51X2
    Philips Semiconductors
    Preliminary data
    P89C51RA2/RB2/RC2/RD2xx
    80C51 8-bit Flash microcontroller family
    8KB/16KB/32KB/64KB ISP/IAP Flash with 512B/512B/512B/1KB RAM
    2002 Jul 18
    21
    FULL-DUPLEX ENHANCED UART
    Standard UART operation
    The serial port is full duplex, meaning it can transmit and receive
    simultaneously. It is also receive-buffered, meaning it can
    commence reception of a second byte before a previously received
    byte has been read from the register. (However, if the first byte still
    hasn’t been read by the time reception of the second byte is
    complete, one of the bytes will be lost.) The serial port receive and
    transmit registers are both accessed at Special Function Register
    SBUF. Writing to SBUF loads the transmit register, and reading
    SBUF accesses a physically separate receive register.
    The serial port can operate in 4 modes:
    Mode 0:
    Serial data enters and exits through RxD. TxD outputs
    the shift clock. 8 bits are transmitted/received (LSB first).
    The baud rate is fixed at 1/12 the oscillator frequency in
    12-clock mode or 1/6 the oscillator frequency in 6-clock
    mode.
    Mode 1:
    10 bits are transmitted (through TxD) or received
    (through RxD): a start bit (0), 8 data bits (LSB first), and
    a stop bit (1). On receive, the stop bit goes into RB8 in
    Special Function Register SCON. The baud rate is
    variable.
    Mode 2:
    11 bits are transmitted (through TxD) or received
    (through RxD): start bit (0), 8 data bits (LSB first), a
    programmable 9th data bit, and a stop bit (1). On
    Transmit, the 9th data bit (TB8 in SCON) can be
    assigned the value of 0 or 1. Or, for example, the parity
    bit (P, in the PSW) could be moved into TB8. On receive,
    the 9th data bit goes into RB8 in Special Function
    Register SCON, while the stop bit is ignored. The baud
    rate is programmable to either 1/32 or 1/64 the oscillator
    frequency in 12-clock mode or 1/16 or 1/32 the oscillator
    frequency in 6-clock mode.
    Mode 3:
    11 bits are transmitted (through TxD) or received
    (through RxD): a start bit (0), 8 data bits (LSB first), a
    programmable 9th data bit, and a stop bit (1). In fact,
    Mode 3 is the same as Mode 2 in all respects except
    baud rate. The baud rate in Mode 3 is variable.
    In all four modes, transmission is initiated by any instruction that
    uses SBUF as a destination register. Reception is initiated in Mode 0
    by the condition RI = 0 and REN = 1. Reception is initiated in the
    other modes by the incoming start bit if REN = 1.
    Multiprocessor Communications
    Modes 2 and 3 have a special provision for multiprocessor
    communications. In these modes, 9 data bits are received. The 9th
    one goes into RB8. Then comes 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 SCON. 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 in that the
    9th bit is 1 in an address byte and 0 in a data byte. With SM2 = 1, no
    slave will be interrupted by a data byte. 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 be coming.
    The slaves that weren’t being addressed leave their SM2s set and
    go on about their business, ignoring the coming data bytes.
    SM2 has no effect in Mode 0, and in Mode 1 can be used to check
    the validity of the stop bit. In a Mode 1 reception, if SM2 = 1, the
    receive interrupt will not be activated unless a valid stop bit is
    received.
    Serial Port Control Register
    The serial port control and status register is the Special Function
    Register SCON, shown in Figure 12. This register contains not only
    the mode selection bits, but also the 9th data bit for transmit and
    receive (TB8 and RB8), and the serial port interrupt bits (TI and RI).
    Baud Rates
    The baud rate in Mode 0 is fixed: Mode 0 Baud Rate = Oscillator
    Frequency / 12 (12-clock mode) or / 6 (6-clock mode). The baud
    rate in Mode 2 depends on the value of bit SMOD in Special
    Function Register PCON. If SMOD = 0 (which is the value on reset),
    and the port pins in 12-clock mode, the baud rate is 1/64 the
    oscillator frequency. If SMOD = 1, the baud rate is 1/32 the oscillator
    frequency. In 6-clock mode, the baud rate is 1/32 or 1/16 the
    oscillator frequency, respectively.
    Mode 2 Baud Rate =
    2
    SMOD
    n
    (Oscillator Frequency)
    Where:
    n = 64 in 12-clock mode, 32 in 6-clock mode
    The baud rates in Modes 1 and 3 are determined by the Timer 1 or
    Timer 2 overflow rate.
    Using Timer 1 to Generate Baud Rates
    When Timer 1 is used as the baud rate generator (T2CON.RCLK
    = 0, T2CON.TCLK = 0), the baud rates in Modes 1 and 3 are
    determined by the Timer 1 overflow rate and the value of SMOD as
    follows:
    Mode 1, 3 Baud Rate =
    2
    SMOD
    n
    (Timer 1 Overflow Rate)
    Where:
    n = 32 in 12-clock mode, 16 in 6-clock mode
    The Timer 1 interrupt should be disabled in this application. The
    Timer itself can be configured for either “timer” or “counter”
    operation, and in any of its 3 running modes. In the most typical
    applications, it is configured for “timer” operation, in the auto-reload
    mode (high nibble of TMOD = 0010B). In that case the baud rate is
    given by the formula:
    Mode 1, 3 Baud Rate =
    2
    SMOD
    n
    Oscillator Frequency
    12
    [256–(TH1)]
    Where:
    n = 32 in 12-clock mode, 16 in 6-clock mode
    One can achieve very low baud rates with Timer 1 by leaving the
    Timer 1 interrupt enabled, and configuring the Timer to run as a
    16-bit timer (high nibble of TMOD = 0001B), and using the Timer 1
    interrupt to do a 16-bit software reload. Figure 13 lists various
    commonly used baud rates and how they can be obtained from
    Timer 1.
    相關(guān)PDF資料
    PDF描述
    P89C51X2BA 80C51 8-bit Flash microcontroller family
    P89C51X2BBD 80C51 8-bit Flash microcontroller family
    P89C51X2BN 80C51 8-bit Flash microcontroller family
    P89C51X2FA 80C51 8-bit Flash microcontroller family
    P89C51UBBB 80C51 8-bit microcontroller family 4K/8K/16K/32K Flash
    相關(guān)代理商/技術(shù)參數(shù)
    參數(shù)描述
    P89C51X2BA 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:80C51 8-bit Flash microcontroller family
    P89C51X2BBD 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:80C51 8-bit Flash microcontroller family
    P89C51X2BN 制造商:NXP Semiconductors 功能描述:
    P89C51X2BN/00,112 功能描述:8位微控制器 -MCU 4K/128 FL 12/6 CLK COMM DIP RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時(shí)鐘頻率:50 MHz 程序存儲(chǔ)器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT
    P89C51X2FA 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:80C51 8-bit Flash microcontroller family
    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

    *
    *
    *