Rainbow Electronics MAX16066 - Manual (Page 42)

12-Channel/8-Channel, Flash-Configurable System
Managers with Nonvolatile Fault Registers
MAX16065/MAX16066
42 _____________________________________________________________________________________
Restrictions When Writing to Flash
Flash must be written to 8 bytes at a time. The initial
address must be aligned to 8-byte boundaries—the 3
LSBs of the initial address must be ‘000’. Write the 8
bytes using a single block-write command or using 8
successive Write Byte commands.
Send Byte
The send byte protocol allows the master device to
send one byte of data to the slave device (see Figure
14). The send byte presets a register pointer address
for a subsequent read or write. The slave sends a NACK
instead of an ACK if the master tries to send a memory
address or command code that is not allowed. If the
master sends A5h or A6h, the data is ACK, because this
could be the start of the write block or read block. If the
master sends a STOP condition before the slave asserts
an ACK, the internal address pointer does not change.
If the master sends A7h, this signifies a software reboot.
The send byte procedure is the following:
1) The master sends a START condition.
2) The master sends the 7-bit slave address and a write
bit (low).
3) The addressed slave asserts an ACK on SDA.
4) The master sends an 8-bit memory address or com-
mand code.
5) The addressed slave asserts an ACK (or NACK)
on SDA.
6) The master sends a STOP condition.
Receive Byte
The receive byte protocol allows the master device to
read the register content of the MAX16065/MAX16066
(see Figure 14). The flash or register address must be
preset with a send byte or write word protocol first. Once
the read is complete, the internal pointer increases by
one. Repeating the receive byte protocol reads the con-
tents of the next address. The receive byte procedure
follows:
1) The master sends a START condition.
2) The master sends the 7-bit slave address and a read
bit (high).
3) The addressed slave asserts an ACK on SDA.
4) The slave sends 8 data bits.
5 The master asserts a NACK on SDA.
6) The master generates a STOP condition.
Write Byte
The write byte protocol (see Figure 14) allows the mas-
ter device to write a single byte in the default page,
extended page, or flash page, depending on which
Figure 13. Acknowledge
SCL
1
S
2 8 9
SDA BY
TRANSMITTER
SDA BY
RECEIVER
CLOCK PULSE FOR ACKNOWLEDGE
NACK
ACK