AT91SAM7S256D-AU Atmel, AT91SAM7S256D-AU Datasheet - Page 326

• Manufacturer Part Number: AT91SAM7S256D-AU
• Description: ARM Microcontrollers - MCU 256K Flash SRAM 64K ARM based MCU
• Manufacturer: Atmel
• Series: SAM7S256r

Specifications of AT91SAM7S256D-AU

• Rohs: yes
• Core: ARM
• Processor Series: AT91SAM
• Data Bus Width: 16 bit/32 bit
• Maximum Clock Frequency: 55 MHz
• Program Memory Size: 256 KB
• Data Ram Size: 64 KB
• On-chip Adc: Yes
• Operating Supply Voltage: 3 V to 3.6 V
• Operating Temperature Range: - 40 C to + 85 C
• Package / Case: LQFP-64
• Mounting Style: SMD/SMT
• Interface Type: 2-Wire, I2S, SPI, USART
• Length: 7 mm

Figure 30-11. Master Write with One, Two or Three Bytes Internal Address and One Data Byte
Figure 30-12. Master Read with One, Two or Three Bytes Internal Address and One Data Byte
30.7.6.2
TWD
TWD
TWD
TWD
TWD
TWD
Three bytes internal address
Two bytes internal address
One byte internal address
Three bytes internal address
Two bytes internal address
One byte internal address
For a slave address higher than 7 bits, the user must configure the address size (IADRSZ) and set the other slave
address bits in the internal address register (TWI_IADR). The two remaining Internal address bytes, IADR[15:8]
and IADR[23:16] can be used the same as in 7-bit Slave Addressing.
Example: Address a 10-bit device (10-bit device address is b1 b2 b3 b4 b5 b6 b7 b8 b9 b10)
Figure 30-13
addresses to access the device.
Figure 30-13. Internal Address Usage
S
S
S
1. Program IADRSZ = 1,
2. Program DADR with 1 1 1 1 0 b1 b2 (b1 is the MSB of the 10-bit address, b2, etc.)
3. Program TWI_IADR with b3 b4 b5 b6 b7 b8 b9 b10 (b10 is the LSB of the 10-bit address)
4.
• N
• DADR
• IADR
S
S
S
10-bit Slave Addressing
DADR
DADR
DADR
DADR
DADR
DADR
below shows a byte write to an Atmel AT24LC512 EEPROM. This demonstrates the use of internal
Not Acknowledge
Device Address
Internal Address
W
W
W
W
W
W
A
A
A
S
A
R
T
T
IADR(23:16)
M
A
A
A
S
B
IADR(15:8)
IADR(7:0)
Address
Device
IADR(23:16)
IADR(15:8)
IADR(7:0)
0
S
B
L
W
R
W
T
E
R
I
/
A
A
A
C
A
K
WORD ADDRESS
M
S
B
IADR(15:8)
Sr
IADR(7:0)
A
A
A
FIRST
DADR
IADR(15:8)
IADR(7:0)
DATA
A
C
K
A
A
R
WORD ADDRESS
SECOND
Sr
IADR(7:0)
A
A
A
A
DADR
S
B
L
A
C
K
IADR(7:0)
P
DATA
DATA
A
SAM7S Series [DATASHEET]
DATA
Sr
R
A
A
N
A
DADR
A
C
K
DATA
O
S
T
P
6175M–ATARM–26-Oct-12
P
P
DATA
DATA
R
N
P
A
N
A
P
P
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