71M6545/71M6545H Data Sheet
?
?
UART0 RX: Serial input data are applied at this pin. Conforming to RS-232 standard, the bytes are
input LSB first.
UART0 TX: This pin is used to output the serial data. The bytes are output LSB first.
The 71M6545/H has several UART-related registers for the control and buffering of serial data.
A single SFR register serves as both the transmit buffer and receive buffer ( S0BUF , SFR 0x99 for UART0).
When written by the MPU, SxBUF acts as the transmit buffer, and when read by the MPU, it acts as the
receive buffer. Writing data to the transmit buffer starts the transmission by the UART. Received data are
available by reading from the receive buffer. The UART can simultaneously transmit and receive data.
WDCON[7] (SFR 0xD8) selects whether timer 1 or the internal baud rate generator is used. All UART
transfers are programmable for parity enable, parity, 2 stop bits/1 stop bit and XON/XOFF options for
variable communication baud rates from 300 to 38400 bps. Table 16 shows how the baud rates are
calculated. Table 17 shows the selectable UART operation modes.
Table 16: Baud Rate Generation
Using Timer 1
( WDCON[7] = 0)
Using Internal Baud Rate Generator
( WDCON[7] = 1)
UART0
UART1
2 smod * f CKMPU / (384 * (256- TH1 ))
N/A
2 smod * f CKMPU /(64 * (2 10 - S0REL ))
f CKMPU /(32 * (2 10 - S1REL ))
S0REL and S1REL are 10-bit values derived by combining bits from the respective timer reload registers.
( S0RELL, S0RELH, S1RELL, S1RELH are SFR 0xAA, SFR 0xBA, SFR 0x9D and SFR 0xBB , respectively) SMOD
is the SMOD bit in the SFR PCON register ( SFR 0x87 ). TH1 (SFR 0x8D) is the high byte of timer 1.
Table 17: UART Modes
UART 0
UART 1
Mode 0
Mode 1
Mode 2
Mode 3
N/A
Start bit, 8 data bits, stop bit, variable
baud rate (internal baud rate generator
or timer 1)
Start bit, 8 data bits, parity, stop bit,
fixed baud rate 1/32 or 1/64 of f CKMPU
Start bit, 8 data bits, parity, stop bit,
variable baud rate (internal baud rate
generator or timer 1)
Start bit, 8 data bits, parity, stop bit, variable
baud rate (internal baud rate generator)
Start bit, 8 data bits, stop bit, variable baud
rate (internal baud rate generator)
N/A
N/A
Parity of serial data is available through the P flag of the accumulator. 7-bit serial modes with
parity, such as those used by the FLAG protocol, can be simulated by setting and reading bit 7 of
8-bit output data. 7-bit serial modes without parity can be simulated by setting bit 7 to a constant 1.
8-bit serial modes with parity can be simulated by setting and reading the 9 th bit, using the control
bits TB80 ( S0CON [ 3 ]) and TB81 ( S1CON[3] ) in the S0CON ( SFR 0x98 ) and S1CON ( SFR 0x9B ) registers
for transmit and RB81 ( S1CON[2] ) for receive operations.
All supported operation modes use oversampling for the incoming bit stream when receiving data. Each
bit is sampled three times at the projected middle of the bit duration. This technique allows for deviations
of the received baud rate from nominal of up to 3.5%.
The feature of receiving 9 bits (Mode 3 for UART0) can be used as handshake signals for inter-processor
communication in multi-processor systems. In this case, the slave processors have bit SM20 ( S0CON[5] )
for UART0, set to 1. When the master processor outputs the slave’s address, it sets the 9 th bit to 1, causing a
serial port receive interrupt in all the slaves. The slave processors compare the received byte with their
address. If there is a match, the addressed slave clears SM20 or SM21 and receive the rest of the message.
v2
37
相关PDF资料
720-10007-00300 CBL D-SUB 9PIN FMAL-25PIN FML 3M
720-10010-00025 CBL DSUB 9PIN FML-25PIN MAL .25M
720-10020-00300 CBL DSUB 9PIN FML-9PIN MALE 3M
720-10021-00300 CBL DSUB 9PIN FML-9PIN FEMAL 3M
72231-0881 8 POS T/P SHLD 4 GR ASSY
7250B PANEL KIT BOTTOM FOR R-1220 CASE
731-10061-00200 CBL DSUB HD 15FEMAL-15MALE 2.0M
73304-111 MJ HOR ESMT 8/8 H/O T&R
相关代理商/技术参数
71M6545-IGTR/F 功能描述:计量片上系统 - SoC Metrology Proc. (3P 64K Flsh .1%) RoHS:否 制造商:Maxim Integrated 核心:80515 MPU 处理器系列:71M6511 类型:Metering SoC 最大时钟频率:70 Hz 程序存储器大小:64 KB 数据 RAM 大小:7 KB 接口类型:UART 可编程输入/输出端数量:12 片上 ADC: 安装风格:SMD/SMT 封装 / 箱体:LQFP-64 封装:Reel
71M6545T-IGT/F 制造商:Maxim Integrated Products 功能描述:METROLOGY PROCESSORS - Rail/Tube
71M6545T-IGTR/F 制造商:Maxim Integrated Products 功能描述:3-PHASE AFE, 32KB FLASH, PRES TEMP SENSOR - Tape and Reel
71M6601 制造商:MAXIM 制造商全称:Maxim Integrated Products 功能描述:On-Chip Temperature Sensor Enables Localized Digital Temperature On-Chip Power Monitoring
71M6601-IF 制造商:MAXIM 制造商全称:Maxim Integrated Products 功能描述:On-Chip Temperature Sensor Enables Localized Digital Temperature On-Chip Power Monitoring
71M6601-IL 制造商:MAXIM 制造商全称:Maxim Integrated Products 功能描述:On-Chip Temperature Sensor Enables Localized Digital Temperature On-Chip Power Monitoring
71M6601-IL/F 功能描述:模数转换器 - ADC Isolated Sensor IC RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32
71M6601-ILF 制造商:MAXIM 制造商全称:Maxim Integrated Products 功能描述:On-Chip Temperature Sensor Enables Localized Digital Temperature On-Chip Power Monitoring