参数资料
型号: SPMC16V1CPU20
厂商: MOTOROLA INC
元件分类: 微控制器/微处理器
英文描述: 16-BIT, MROM, 20.97 MHz, MICROCONTROLLER, PQFP100
封装: TQFP-100
文件页数: 12/128页
文件大小: 571K
代理商: SPMC16V1CPU20
MC68HC16V1
MOTOROLA
MC68HC16V1TS/D
109
SCCR0 contains a baud rate selection parameter. Baud rate must be set before the SCI is enabled. The
CPU can read and write this register at any time.
Bits [15:13] — Not Implemented
SCBR[12:0] — Baud Rate
SCI baud rate is programmed by writing a 13-bit value to BR. The baud rate is derived from the MCU
system clock by a modulus counter.
The SCI receiver operates asynchronously. An internal clock is necessary to synchronize with an in-
coming data stream. The SCI baud rate generator produces a receiver sampling clock with a frequency
16 times that of the expected baud rate of the incoming data. The SCI determines the position of bit
boundaries from transitions within the received waveform, and adjusts sampling points to the proper po-
sitions within the bit period. Receiver sampling rate is always 16 times the frequency of the SCI baud
rate, which is calculated as follows:
or
where SCBR[12:0] is in the range {1, 2, 3, …, 8191}
Writing a value of zero to SCBR[12:0] disables the baud rate generator.
Table 58 lists the SCBR[12:0] settings for standard and maximum baud rates using a 20.97 MHz sys-
tem clock.
SCCR0 — SCI Control Register 0
$YFFC08
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
SCBR[12:0]
RESET:
0
1
0
Table 58 SCI Baud Rates
Nominal Baud Rate Actual Rate with
20.97 MHz Clock
SCBR[12:0] Value
64
110
110.0
$1745
300
300.1
$0888
600
600.1
$0444
1200
1200.3
$0222
2400
2400.6
$0111
4800
4783.6
$0089
9600
9637.6
$0044
19200
19275.3
$0022
38400
38550.6
$0011
76800
72817.8
$0009
Maximum Rate
655360.0
$0001
SCI Baud Rate
System Clock
32
SCBR[12:0]
×
--------------------------------------------
=
SCBR[12:0]
System Clock
32
SCI Baud Rate Desired
×
---------------------------------------------------------------------------
=
相关PDF资料
PDF描述
S1C60N05F0A0100 MICROCONTROLLER, PQFP60
SC3S12P128J0CLHR 16-BIT, MROM, 1.05 MHz, MICROCONTROLLER, PQFP64
SC3S12P128J0CLH 16-BIT, MROM, 1.05 MHz, MICROCONTROLLER, PQFP64
SC3S12P128J0CQKR 16-BIT, MROM, 1.05 MHz, MICROCONTROLLER, PQFP80
S908QY2AD1MDW 8-BIT, FLASH, 8 MHz, MICROCONTROLLER, PDSO16
相关代理商/技术参数
参数描述
SPMC387-01 制造商:SSDI 制造商全称:Solid States Devices, Inc 功能描述:50 WATT RADIATION HARDENED DC-DC POWER CONVERTER
SPMC68CK338CPV14 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:32-Bit Modular Microcontroller
SPMC802B 制造商:未知厂家 制造商全称:未知厂家 功能描述:32-pin General Purpose Microcontroller (OTP)
SPMC802B-C 制造商:未知厂家 制造商全称:未知厂家 功能描述:32-pin General Purpose Microcontroller (OTP)
SPMC802B-PD03 制造商:未知厂家 制造商全称:未知厂家 功能描述:32-pin General Purpose Microcontroller (OTP)