參數(shù)資料
型號: ST10F269DIETR
廠商: STMICROELECTRONICS
元件分類: 微控制器/微處理器
英文描述: 16-BIT, FLASH, 32 MHz, MICROCONTROLLER, UUC
封裝: DIE
文件頁數(shù): 89/161頁
文件大?。?/td> 1595K
代理商: ST10F269DIETR
ST10F269-T3
33/160
5.6.5 - Choosing the Baud Rate for the BSL
The calculation of the serial Baud rate for ASC0
from the length of the first zero Byte that is
received, allows the operation of the bootstrap
loader of the ST10F269-T3 with a wide range of
Baud rates. However, the upper and lower limits
have to be kept, in order to insure proper data
transfer.
The ST10F269-T3 uses timer T6 to measure the
length of the initial zero Byte. The quantization
uncertainty of this measurement implies the first
deviation from the real Baud rate, the next
deviation is implied by the computation of the
S0BRL reload value from the timer contents. The
formula below shows the association:
For a correct data transfer from the host to the
ST10F269-T3 the maximum deviation between
the internal initialized Baud rate for ASC0 and the
real Baud rate of the host should be below 2.5%.
The deviation (FB, in percent) between host Baud
rate
and
ST10F269-T3
Baud
rate
can
be
calculated via the formula below:
Note: Function (FB) does not consider the
tolerances of oscillators and other devices
supporting the serial communication.
This Baud rate deviation is a nonlinear function
depending on the CPU clock and the Baud rate of
the host. The maxima of the function (FB)
increase with the host Baud rate due to the
smaller Baud rate pre-scaler factors and the
implied higher quantization error (see Figure 8).
The minimum Baud rate (BLow in the Figure 8) is
determined by the maximum count capacity of
timer T6, when measuring the zero Byte, and it
depends on the CPU clock. Using the maximum
T6 count 216 in the formula the minimum Baud
rate can be calculated. The lowest standard Baud
rate in this case would be 1200 Baud. Baud rates
below BLow would cause T6 to overflow. In this
case ASC0 cannot be initialized properly.
The maximum Baud rate (BHigh in the Figure 8)
is the highest Baud rate where the deviation still
does not exceed the limit, so all Baud rates
between BLow and BHigh are below the deviation
limit. The maximum standard Baud rate that fulfills
this requirement is 19200 Baud.
Higher Baud rates, however, may be used as
long as the actual deviation does not exceed the
limit. A certain Baud rate (marked ’I’ in Figure 8)
may violate the deviation limit, while an even
higher Baud rate (marked ’II’ in Figure 8) stays
very well below it. This depends on the host
interface.
f
CPU
32
S0BRL
1
+
()
×
------------------------------------------------
BST10F269-T3 =
S0BRL
T6
36
72
--------------------
=
T6
9
4
---
f
CPU
B
Host
-----------------
×
=
,
F
B
C ontr
B
Ho st
B
C ontr
--------------------------------------------
100
×
=
% ,
F
B
2.5
%
Figure 8 : Baud Rate Deviation Between Host and ST10F269-T3
BLow
2.5%
FB
BHigh
I
II
BHOST
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
ST10F269-DP 功能描述:16位微控制器 - MCU 16-bit MCU MAC 256 Kbyte Flash RoHS:否 制造商:Texas Instruments 核心:RISC 處理器系列:MSP430FR572x 數(shù)據(jù)總線寬度:16 bit 最大時鐘頻率:24 MHz 程序存儲器大小:8 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:2 V to 3.6 V 工作溫度范圍:- 40 C to + 85 C 封裝 / 箱體:VQFN-40 安裝風(fēng)格:SMD/SMT
ST10F269-DPB 功能描述:16位微控制器 - MCU 16-bit MCU MAC 256 Kbyte Flash RoHS:否 制造商:Texas Instruments 核心:RISC 處理器系列:MSP430FR572x 數(shù)據(jù)總線寬度:16 bit 最大時鐘頻率:24 MHz 程序存儲器大小:8 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:2 V to 3.6 V 工作溫度范圍:- 40 C to + 85 C 封裝 / 箱體:VQFN-40 安裝風(fēng)格:SMD/SMT
ST10F269-DPR 功能描述:16位微控制器 - MCU 16Bit MCU 256K BYTE FLASH,12K BYTE RAM RoHS:否 制造商:Texas Instruments 核心:RISC 處理器系列:MSP430FR572x 數(shù)據(jù)總線寬度:16 bit 最大時鐘頻率:24 MHz 程序存儲器大小:8 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:2 V to 3.6 V 工作溫度范圍:- 40 C to + 85 C 封裝 / 箱體:VQFN-40 安裝風(fēng)格:SMD/SMT
ST10F269DT3 功能描述:16位微控制器 - MCU 16Bit MCU 256K BYTE FLASH,12K BYTE RAM RoHS:否 制造商:Texas Instruments 核心:RISC 處理器系列:MSP430FR572x 數(shù)據(jù)總線寬度:16 bit 最大時鐘頻率:24 MHz 程序存儲器大小:8 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:2 V to 3.6 V 工作溫度范圍:- 40 C to + 85 C 封裝 / 箱體:VQFN-40 安裝風(fēng)格:SMD/SMT
ST10F269DTR3 功能描述:16位微控制器 - MCU 16-bit MCU MAC unit 256 Kbyte Flash RoHS:否 制造商:Texas Instruments 核心:RISC 處理器系列:MSP430FR572x 數(shù)據(jù)總線寬度:16 bit 最大時鐘頻率:24 MHz 程序存儲器大小:8 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:2 V to 3.6 V 工作溫度范圍:- 40 C to + 85 C 封裝 / 箱體:VQFN-40 安裝風(fēng)格:SMD/SMT