ADM1065 Analog Devices, ADM1065 Datasheet - Page 24

• Manufacturer Part Number: ADM1065
• Manufacturer: Analog Devices

Specifications of ADM1065

• # Supplies Monitored: 10
• Volt Monitoring Accuracy: 1%
• # Output Drivers: 10
• Fet Drive/enable Output: Both
• Package: 40 ld LFCSP ,48 ld TQFP

ADM1065
Write Byte/Word
In a write byte/word operation, the master device sends a
command byte and one or two data bytes to the slave device,
as follows:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10. The master asserts a stop condition on SDA to end the
In the ADM1065, the write byte/word protocol is used for three
purposes:
•
•
•
1
S
The master device asserts a start condition on SDA.
The master sends the 7-bit slave address followed by the
write bit (low).
The addressed slave device asserts an ACK on SDA.
The master sends a command code.
The slave asserts an ACK on SDA.
The master sends a data byte.
The slave asserts an ACK on SDA.
The master sends a data byte or asserts a stop condition.
The slave asserts an ACK on SDA.
transaction.
To write a single byte of data to the RAM. In this case, the
command byte is RAM Address 0x00 to RAM Address
0xDF, and the only data byte is the actual data, as shown in
Figure 31.
To set up a 2-byte EEPROM address for a subsequent read,
write, block read, block write, or page erase. In this case,
the command byte is the high byte of EEPROM Address
0xF8 to EEPROM Address 0xFB. The only data byte is the
low byte of the EEPROM address, as shown in Figure 32.
Because a page consists of 32 bytes, only the three MSBs of the
address low byte are important for page erasure. The lower
five bits of the EEPROM address low byte specify the
addresses within a page and are ignored during an erase
operation.
To write a single byte of data to the EEPROM. In this case,
the command byte is the high byte of EEPROM Address 0xF8
to EEPROM Address 0xFB. The first data byte is the low
byte of the EEPROM address, and the second data byte is
the actual data, as shown in Figure 33.
ADDRESS
SLAVE
1
S
ADDRESS
2
SLAVE
1
S
2
ADDRESS
Figure 33. Single Byte Write to the EEPROM
SLAVE
W A
Figure 31. Single Byte Write to the RAM
Figure 32. Setting an EEPROM Address
2
3
W A
(0xF8 TO 0xFB)
3
HIGH BYTE
W A
ADDRESS
EEPROM
(0xF8 TO 0xFB)
3
HIGH BYTE
4
ADDRESS
EEPROM
(0x00 TO 0xDF)
ADDRESS
4
RAM
4
A
5
(0x00 TO 0xFF)
A
5
LOW BYTE
ADDRESS
EEPROM
(0x00 TO 0xFF)
A
5
LOW BYTE
6
ADDRESS
EEPROM
DATA
6
6
7
A
A
7
DATA
8
P
8
A
7
P
8
A
9
10
P
Rev. D | Page 24 of 28
Block Write
In a block write operation, the master device writes a block of data
to a slave device. The start address for a block write must be set
previously. In the ADM1065, a send byte operation sets a RAM
address, and a write byte/word operation sets an EEPROM address,
as follows:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10. The master asserts a stop condition on SDA to end the
Unlike some EEPROM devices that limit block writes to within
a page boundary, there is no limitation on the start address
when performing a block write to EEPROM, except when
•
•
Note that the ADM1065 features a clock extend function for writes
to the EEPROM. Programming an EEPROM byte takes approxi-
mately 250 μs, which limits the SMBus clock for repeated or
block write operations. The ADM1065 pulls SCL low and extends
the clock pulse when it cannot accept any more data.
S
1
ADDRESS
SLAVE
The master device asserts a start condition on SDA.
The master sends the 7-bit slave address followed by
the write bit (low).
The addressed slave device asserts an ACK on SDA.
The master sends a command code that tells the slave
device to expect a block write. The ADM1065 command
code for a block write is 0xFC (1111 1100).
The slave asserts an ACK on SDA.
The master sends a data byte that tells the slave device how
many data bytes are being sent. The SMBus specification
allows a maximum of 32 data bytes in a block write.
The slave asserts an ACK on SDA.
The master sends N data bytes.
The slave asserts an ACK on SDA after each data byte.
transaction.
There must be at least N locations from the start address to
the highest EEPROM address (0xFBFF) to avoid writing to
invalid addresses.
An address crosses a page boundary. In this case, both
pages must be erased before programming.
2
W A
Figure 34. Block Write to the EEPROM or RAM
3
COMMAND 0xFC
(BLOCK WRITE)
4
A
5
COUNT
BYTE
6
A
7
DATA
8
1
A
9
DATA
2
A
DATA
N
A P
10