SML2108
PRELIMINARY
S
T
A
R
T
N S
A T
C O
K P
R
/
W
A
C
K
Optional
Master
SDA
x x x
x x x x x x x
x x
x x
R
1 0 1 0
A
C
K
Slave
2053 Fig12
Figure 12. Read
S
T
A
R
T
S
T
O
P
R
/
W
Master
SDA
x x x
x x x x x x x x
x x
x x
1 0 1 0
W
A
C
K
A
C
K
A
C
K
Slave
2053 Fig13
Figure 13. Write
InthewritemodetheSML2108receiveseightbitsofdata, Sequential READ
then generates an Acknowledge signal. It will continue to
generate ACKs until a Stop condition is generated by the
Master. See Figure 13.
Sequential Reads can be initiated as either a current
address Read or a random access Read. The first word
is transmitted as with the other byte read modes (current
address byte Read or random address byte Read). How-
ever, the Master now responds with an Acknowledge,
Random Address Read
Random address Read operations allow the Master to indicating that it requires additional data. The SML2108
access any memory location in a random fashion. This continues to output data for each Acknowledge received.
operation involves a two-step process. First, the master The Master terminates the sequential Read operation by
issuesawritecommandwhichincludesthestartcondition not responding with an Acknowledge, and issues a Stop
and the Slave address field (with the R/W bit set to Write) condition. During a sequential read operation the internal
followed by the address of the word it is to read. This address counter is automatically incremented with each
procedure sets the internal address counter of the Acknowledgesignal. ForReadoperationsalladdressbits
SML2108 to the desired address. After the word address areincremented,allowingtheentirearraytobereadusing
acknowledge is received by the Master, it immediately a single Read command. After a count of the last memory
reissues a start condition followed by another Slave ad- address the address counter will ‘roll-over’ and the
dressfieldwiththeR/WbitsettoRead. TheSML2108will memory will continue to output data.
respondwithanAcknowledgeandthentransmitthe8data
The protocol for reading and writing to the registers and
bits stored at the addressed location. At this point, the
the lookup table are illustrated in Figures 14 through 24.
Master does not acknowledge the transmission, but does
generate a Stop condition. The SML2108 discontinues
data transmission.
SUMMIT MICROELECTRONICS, Inc.
2053 2.2 11/07/00
15
SUMMIT [ SUMMIT MICROELECTRONICS, INC. ]
