Toshiba TLCS-900/L1 Series Manual page 169

(3) 1-word data transfer
Check the <MST> by the INTSBI interrupt process after the 1-word data transfer
is completed, and determine whether the mode is a master or slave.
a. If <MST> = 1 (Master mode)
Check the <TRX> and determine whether the mode is a transmitter or receiver.
When the <TRX> = 1 (Transmitter mode)
Check the <LRB>. When <LRB> is 1, a receiver does not request data.
Implement the process to generate a stop condition (Refer to 3.10.6 (4)) and
terminate data transfer.
When the <LRB> is 0, the receiver is requests new data. When the next
transmitted data is 8 bits, write the transmitted data to SBI0DBR. When the
next transmitted data is other than 8 bits, set the BC<2:0> <ACK> and write the
transmitted data to SBI0DBR. After written the data, <PIN> becomes 1, a serial
clock pulse is generated for transferring a new 1 word of data from the SCL pin,
and then the 1-word data is transmitted. After the data is transmitted, an
INTSBI interrupt request occurs. The <PIN> becomes 0 and the SCL line is
pulled down to the low level. If the data to be transferred is more than 1 word in
length, repeat the procedure from the <LRB> checking above.
Write to SBI0DBR
1
SCL line
D7
SDA line
<PIN>
INTSBI
interrupt request
Output from master
Output from slave
Figure 3.10.14 Example in which BC<2:0> = 000 and <ACK> = 1 in Transmitter Mode
2 3 4 5
D6 D5 D4 D3
91C824-167
6 7 8 9
D2 D1 D0 ACK
TMP91C824
Acknowledge signal
from a receive
2008-02-20