參數資料
型號: ADUC832BCP
廠商: ANALOG DEVICES INC
元件分類: 微控制器/微處理器
英文描述: MicroConverter, 12-Bit ADCs and DACs with Embedded 62 kBytes Flash MCU
中文描述: 8-BIT, FLASH, 16.78 MHz, MICROCONTROLLER, PQFP52
封裝: MO-112AC-1, MQFP-52
文件頁數: 25/80頁
文件大?。?/td> 1311K
代理商: ADUC832BCP
REV. 0
ADuC832
–25–
The DMA logic operates from the ADC clock and uses pipelining
to perform the ADC conversions and access the external memory
at the same time. The time it takes to perform one ADC conver-
sion is called a DMA cycle. The actions performed by the logic
during a typical DMA cycle are shown in the following diagram.
PWRITE ADC RESULT
TO NEXT DMA CYCLE
CONVERT CHANNEL READ DURING PREVIOUS DMA CYCLE
DMA CYCLE
Figure 16. DMA Cycle
From the previous diagram, it can be seen that during one DMA
cycle, the following actions are performed by the DMA logic:
1. An ADC conversion is performed on the channel whose ID
was read during the previous cycle.
2. The 12-bit result and the channel ID of the conversion per-
formed in the previous cycle is written to the external memory.
3. The ID of the next channel to be converted is read from
external memory.
For the previous example, the complete flow of events is shown
in Figure 16. Because the DMA logic uses pipelining, it takes
three cycles before the first correct result is written out.
Micro Operation during ADC DMA Mode
During ADC DMA mode, the MicroConverter core is free to
continue code execution, including general housekeeping and
communication tasks. However, note that MCU core accesses to
Ports 0 and 2 (which of course are being used by the DMA con-
troller) are gated
OFF
during ADC DMA mode of operation.
This means that even though the instruction that accesses the
external ports 0 or 2 will appear to execute, no data will be seen
at these external Ports as a result. Note that during DMA to the
internally contained XRAM, Ports 0 and 2 are available for use.
The only case in which the MCU will be able to access XRAM
during DMA is when the internal XRAM is enabled and the
section of RAM to which the DMA ADC results are being written
to lies in an external XRAM. Then the MCU will be able to
access the internal XRAM only. This is also the case for use of
the extended stack pointer.
The MicroConverter core can be configured with an interrupt to
be triggered by the DMA controller when it has finished filling
the requested block of RAM with ADC results, allowing the
service routine for this interrupt to postprocess data without any
real-time timing constraints.
ADC Offset and Gain Calibration Coefficients
The ADuC832 has two ADC calibration coefficients, one for
offset calibration and one for gain calibration. Both the offset
and gain calibration coefficients are 14-bit words, and are each
stored in two registers located in the Special Function Register
(SFR) area. The offset calibration coefficient is divided into
ADCOFSH (six bits) and ADCOFSL (eight bits) and the gain
calibration coefficient is divided into ADCGAINH (six bits) and
ADCGAINL (eight bits).
The offset calibration coefficient compensates for dc offset errors
in both the ADC and the input signal. Increasing the offset
coefficient compensates for positive offset, and effectively pushes
the ADC transfer function down. Decreasing the offset coefficient
compensates for negative offset, and effectively pushes the ADC
transfer function up. The maximum offset that can be compensated
is typically
±
5% of V
REF
, which equates to typically
±
125 mV
with a 2.5 V reference.
Similarly, the gain calibration coefficient compensates for dc
gain errors in both the ADC and the input signal. Increasing
the gain coefficient compensates for a smaller analog input signal
range and scales the ADC transfer function up, effectively
increasing the slope of the transfer function. Decreasing the gain
coefficient compensates for a larger analog input signal range and
scales the ADC transfer function down, effectively decreasing
the slope of the transfer function. The maximum analog input
signal range for which the gain coefficient can compensate is
1.025 V
REF
and the minimum input range is 0.975 V
REF
,
which equates to typically
±
2.5% of the reference voltage.
CALIBRATING THE ADC
There are two hardware calibration modes provided that can be
easily initiated by user software. The ADCCON3 SFR is used
to calibrate the ADC. Bit 1 (TYPICAL) and the CS3 to CS0
(ADCCON2) set up the calibration modes.
Device calibration can be initiated to compensate for significant
changes in operating conditions frequency, analog input range,
reference voltage, and supply voltages. In this calibration mode,
offset calibration uses internal AGND selected via ADCCON2
register bits CS3
CS0 (1011) and gain calibration uses internal
V
REF
selected by CS3
CS0 (1100). Offset calibration should be
executed first, followed by gain calibration.
System calibration can be initiated to compensate for both inter-
nal and external system errors. To perform system calibration
using an external reference, tie system ground and reference to
any two of the six selectable inputs. Enable external reference
mode (ADCCON1.6). Select the channel connected to AGND
via CS3
CS0 and perform system offset calibration. Select the
channel connected to V
REF
via CS3
CS0 and perform system
gain calibration.
The ADC should be configured to use settings for an ADCCLK
of divide by 16 and 4 acquisition clocks.
相關PDF資料
PDF描述
ADUC832BS MicroConverter, 12-Bit ADCs and DACs with Embedded 62 kBytes Flash MCU
ADUC834 MicroConverter, Dual 16-/24- Bit ADCs with Embedded 62KB FLASH MCU
ADUC834BS MicroConverter, Dual 16-/24- Bit ADCs with Embedded 62KB FLASH MCU
ADUM1310BRWZ Triple-Channel Digital Isolator with Programmable Default Output
ADUM1310BRWZ-RL Triple-Channel Digital Isolator with Programmable Default Output
相關代理商/技術參數
參數描述
ADUC832BCP-REEL 制造商:Analog Devices 功能描述:MCU 8-Bit ADuC8xx 8052 CISC 62KB Flash 3V/5V 56-Pin LFCSP EP T/R
ADUC832BCPZ 功能描述:IC MCU 62K FLASH ADC/DAC 56LFCSP RoHS:是 類別:集成電路 (IC) >> 嵌入式 - 微控制器, 系列:MicroConverter® ADuC8xx 標準包裝:250 系列:LPC11Uxx 核心處理器:ARM? Cortex?-M0 芯體尺寸:32-位 速度:50MHz 連通性:I²C,Microwire,SPI,SSI,SSP,UART/USART,USB 外圍設備:欠壓檢測/復位,POR,WDT 輸入/輸出數:40 程序存儲器容量:96KB(96K x 8) 程序存儲器類型:閃存 EEPROM 大小:4K x 8 RAM 容量:10K x 8 電壓 - 電源 (Vcc/Vdd):1.8 V ~ 3.6 V 數據轉換器:A/D 8x10b 振蕩器型:內部 工作溫度:-40°C ~ 85°C 封裝/外殼:48-LQFP 包裝:托盤 其它名稱:568-9587
ADUC832BCPZ-REEL 功能描述:IC MCU 62K FLASH ADC/DAC 56LFCSP 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: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 數據轉換器:- 振蕩器型:內部 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
ADUC832BS 制造商:Analog Devices 功能描述:MCU 8-Bit ADuC8xx 8052 CISC 62KB Flash 3.3V/5V 52-Pin MQFP 制造商:Rochester Electronics LLC 功能描述:8BIT CISC 62KB FLASH 16.78MHZ 3.3/5V 52MQFP - Bulk 制造商:Analog Devices 功能描述:8BIT MCU +12BIT ADC LQFP52 832
ADUC832BS-REEL 制造商:Analog Devices 功能描述:MCU 8-Bit ADuC8xx 8052 CISC 62KB Flash 3.3V/5V 52-Pin MQFP T/R