AT91SAM7A1-AU Atmel, AT91SAM7A1-AU Datasheet - Page 277

• Manufacturer Part Number: AT91SAM7A1-AU
• Description: IC ARM7 MCU 32BIT ROMLESS144LQFP
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM7A1-AU

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 40MHz
• Connectivity: CAN, EBI/EMI, SPI, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 49
• Program Memory Type: ROMless
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 144-LQFP
• For Use With: AT91SAM7A1-EK - BOARD EVAL FOR AT91SAM7A1
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Program Memory Size: -

6048B–ATARM–29-Jun-06
Table 25-3
Table 25-3.
Control Field (Standard and Extended Format)
The control field consists of six bits. The format of the control field is different for standard for-
mat and extended format. Frames in standard format include the data length code, the IDE bit,
which is transmitted dominant, and the reserved bit r0. Frames in extended format include the
data length code and two reserved bits, r1 and r0. The reserved bits have to be sent dominant,
but receivers accept dominant and recessive bits in all combinations.
Figure 25-6. Control Field
The number of bytes in the data field is indicated by the data length code. The DLC field is four
bits wide and is transmitted within the control field. Coding of the number of data bytes by the
DLC field is described in
Table 25-4.
Data Frame (Standard and Extended Format)
The admissible numbers of data bytes is 0 to 8. Other values may not be used.
Data Field (Standard and Extended Format)
The data field consists of the data to be transferred within a data frame. It can contain from 0
to 8 bytes, which each contain 8 bits which are transferred MSB first.
Frame Format Type
Standard frame format
Extended frame format
• Data Length Code (Standard and Extended Format)
Number of Data (Bytes)
shows the IDE bit logical value and membership according to frame format type.
Arbitration Field
0
1
2
3
4
5
6
7
8
IDE Bit Logical Value and Membership Depending on Format Type
Data Length Code (D = dominant, R = recessive)
Table
IDE
r1
25-4.
DLC3
IDE Bit Belongs to
Control field
Arbitration field
r0
D
D
D
D
D
D
D
D
R
DLC3
Control Field
DLC Field
DLC2 DLC1 DLC0
DLC2
D
D
D
D
R
R
R
R
D
Data Length Code
Data Field or CRC Field
IDE Bit Logical Value
Dominant
Recessive
DLC1
AT91SAM7A1
D
D
R
R
D
D
R
R
D
DLC0
D
R
D
R
D
R
D
R
D
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