參數(shù)資料
型號: ADUC847BSZ62-5
廠商: Analog Devices Inc
文件頁數(shù): 91/108頁
文件大小: 0K
描述: IC FLASH MCU W/24BIT ADC 52-MQFP
產(chǎn)品培訓模塊: Process Control
標準包裝: 1
系列: MicroConverter® ADuC8xx
核心處理器: 8052
芯體尺寸: 8-位
速度: 12.58MHz
連通性: I²C,SPI,UART/USART
外圍設備: POR,PSM,PWM,溫度傳感器,WDT
輸入/輸出數(shù): 34
程序存儲器容量: 62KB(62K x 8)
程序存儲器類型: 閃存
EEPROM 大小: 4K x 8
RAM 容量: 2.25K x 8
電壓 - 電源 (Vcc/Vdd): 4.75 V ~ 5.25 V
數(shù)據(jù)轉(zhuǎn)換器: A/D 10x24b; D/A 1x12b,2x16b
振蕩器型: 內(nèi)部
工作溫度: -40°C ~ 125°C
封裝/外殼: 52-QFP
包裝: 托盤
產(chǎn)品目錄頁面: 738 (CN2011-ZH PDF)
配用: EVAL-ADUC847QSZ-ND - KIT DEV QUICK START FOR ADUC847
Data Sheet
ADuC845/ADuC847/ADuC848
Rev. C | Page 83 of 108
Timer 3 Generated Baud Rates
The high integer dividers in a UART block mean that high
speed baud rates are not always possible. Also, generating baud
rates requires the exclusive use of a timer, rendering it unusable
for other applications when the UART is required. To address
this problem, the ADuC845/ADuC847/ADuC848 have a
dedicated baud rate timer (Timer 3) specifically for generating
highly accurate baud rates. Timer 3 can be used instead of
Timer 1 or Timer 2 for generating very accurate high speed
UART baud rates including 115200 and 230400. Timer 3 also
allows a much wider range of baud rates to be obtained. In fact,
every desired bit rate from 12 bps to 393216 bps can be
generated to within an error of ±0.8%. Timer 3 also frees up the
other three timers, allowing them to be used for different
applications. A block diagram of Timer 3 is shown in Figure 61.
÷ (1 + T3FD/64)
T3 Rx/Tx
CLOCK
CORE
CLK
T3EN
Rx CLOCK
Tx CLOCK
TIMER 1/TIMER 2
Rx CLOCK
FRACTIONAL
DIVIDER
0
1
TIMER 1/TIMER 2
Tx CLOCK
÷ 16
÷ 2DIV
04741-058
Figure 61. Timer 3, UART Baud Rate
Two SFRs (T3CON and T3FD) are used to control Timer 3.
T3CON is the baud rate control SFR, allowing Timer 3 to be
used to set up the UART baud rate, and to set up the binary
divider (DIV).
The appropriate value to write to the DIV2-1-0 bits can be
calculated using the following formula where fCORE is defined in
PLLCON SFR. Note that the DIV value must be rounded down.
DIV =
)
2
(
log
16
log
×
Rate
Baud
Frequency
Clock
Core
T3FD is the fractional divider ratio required to achieve the
required baud rate. The appropriate value for T3FD can be
calculated with the following formula:
T3FD =
Rate
Baud
Frequency
Clock
Core
DIV
×
1
2
64
Note that T3FD should be rounded to the nearest integer. Once
the values for DIV and T3FD are calculated, the actual baud
rate can be calculated with the following formula:
Actual Baud Rate =
)
64
(
2
1
+
×
T3FD
Frequency
Clock
Core
DIV
For example, to get a baud rate of 9600 while operating at a core
clock frequency of 1.5725 MHz, that is, CD = 3,
DIV = log(1572500/(16 × 9600))/log2 = 3.35 = 3
Note that the DIV result is rounded down.
T3FD = (2 × 1572500)/(231 × 9600) 64 = 18 = 12H
Therefore, the actual baud rate is 9588 bps, which gives an error
of 0.12%.
The T3CON and T3FD registers are used to control Timer 3.
T3CON – Timer 3 Control Register
SFR Address:
9EH
Power-On Default:
00H
Bit Addressable:
No
Table 55. T3CON SFR Bit Designations
Bit No.
Name
Description
7
T3BAUDEN
T3UARTBAUD Enable.
Set to enable Timer 3 to generate the baud rate. When set, PCON.7, T2CON.4, and T2CON.5 are
ignored. Cleared to let the baud rate be generated as per a standard 8052.
6
Not Implemented. Write Don’t Care.
5
Not Implemented. Write Don’t Care.
4
Not Implemented. Write Don’t Care.
3
Not Implemented. Write Don’t Care.
2, 1, 0
DIV2, DIV1, DIV0
Binary Divider
DIV2
DIV1
DIV0
0
Binary Divider 0. See Table 57.
0
1
Binary Divider 1. See Table 57.
0
1
0
Binary Divider 2. See Table 57.
0
1
Binary Divider 3. See Table 57.
1
0
Binary Divider 4. See Table 57.
1
0
1
Binary Divider 5. See Table 57.
1
0
Binary Divider 6. See Table 57.
相關PDF資料
PDF描述
VJ1825Y333JBGAT4X CAP CER 0.033UF 1KV 5% X7R 1825
VJ2220Y684KBCAT4X CAP CER 0.68UF 200V 10% X7R 2220
VI-JTV-IY-F3 CONVERTER MOD DC/DC 5.8V 50W
VI-JTT-IY-F1 CONVERTER MOD DC/DC 6.5V 50W
VI-JTR-IY-F3 CONVERTER MOD DC/DC 7.5V 50W
相關代理商/技術參數(shù)
參數(shù)描述
ADUC847BSZ8-3 功能描述:IC MCU FLASH W/24BIT ADC 52MQFP RoHS:是 類別:集成電路 (IC) >> 嵌入式 - 微控制器, 系列:MicroConverter® ADuC8xx 標準包裝:38 系列:Encore!® XP® 核心處理器:eZ8 芯體尺寸:8-位 速度:5MHz 連通性:IrDA,UART/USART 外圍設備:欠壓檢測/復位,LED,POR,PWM,WDT 輸入/輸出數(shù):16 程序存儲器容量:4KB(4K x 8) 程序存儲器類型:閃存 EEPROM 大小:- RAM 容量:1K x 8 電壓 - 電源 (Vcc/Vdd):2.7 V ~ 3.6 V 數(shù)據(jù)轉(zhuǎn)換器:- 振蕩器型:內(nèi)部 工作溫度:-40°C ~ 105°C 封裝/外殼:20-SOIC(0.295",7.50mm 寬) 包裝:管件 其它名稱:269-4116Z8F0413SH005EG-ND
ADUC847BSZ8-5 功能描述:IC MCU FLASH W/24BIT ADC 52MQFP RoHS:是 類別:集成電路 (IC) >> 嵌入式 - 微控制器, 系列:MicroConverter® ADuC8xx 標準包裝:38 系列:Encore!® XP® 核心處理器:eZ8 芯體尺寸:8-位 速度:5MHz 連通性:IrDA,UART/USART 外圍設備:欠壓檢測/復位,LED,POR,PWM,WDT 輸入/輸出數(shù):16 程序存儲器容量:4KB(4K x 8) 程序存儲器類型:閃存 EEPROM 大小:- RAM 容量:1K x 8 電壓 - 電源 (Vcc/Vdd):2.7 V ~ 3.6 V 數(shù)據(jù)轉(zhuǎn)換器:- 振蕩器型:內(nèi)部 工作溫度:-40°C ~ 105°C 封裝/外殼:20-SOIC(0.295",7.50mm 寬) 包裝:管件 其它名稱:269-4116Z8F0413SH005EG-ND
ADUC848 制造商:AD 制造商全稱:Analog Devices 功能描述:MicroConverter Multichannel 24-/16-Bit ADCs with Embedded 62 kB Flash and Single-Cycle MCU
ADUC848BCP32-3 制造商:Analog Devices 功能描述:10 CHANNEL 16 BIT ADC + FLASH 8 BIT UP - Trays
ADUC848BCP32-5 制造商:Analog Devices 功能描述:10 CHANNEL 16 BIT ADC + FLASH 8 BIT UP - Trays