19 UNIVERSAL SERIAL INTERFACE WITH LCD INTERFACE (USIL)
S1C33L26 TECHNICAL MANUAL
Seiko Epson Corporation
19-17
IMBSY is set to 1 while a stop condition is being generated. When the stop condition is generated, IMBSY
is reset to 0 and IMSTA[2:0] is set to 0x1. Read IMBSY or use an interrupt to check that a stop condition
has been generated. The I
2
C bus subsequently switches to free state.
(5) Generating repeated start condition
To make it possible to continue with a different data transfer after a data transmission has completed, the
I
2
C master can omit stop condition generation and generate a repeated start condition. To generate a re-
peated start condition, perform a start condition generation procedure described in Step (1). Slave address
transmission is subsequently possible with the I
2
C bus remaining in the busy state.
SDA (USIL_DI)
SCL (USIL_CK)
Repeated start condition
5.3.7 Repeated Start Condition
Figure 19.
Data reception in I
2
C master mode
The following describes the data receiving procedure in I
2
C master mode.
START
END
Generate start condition
Generate stop condition
Send slave address and transfer
direction bit
ACK received?
yes
no
Finished?
yes
Receive data
Send ACK
Error handling
no
5.3.8 I
Figure 19.
2
C Master Data Receiving Flow Chart
0x0
Address
0x6
0x2
0x3
A6
A5
D7
D6
D5
D4
D3
D2
D1
D0
A4
A3
A2
A1
A0 R/W = 1
ACK
USIL_CK pin (output)
USIL_CK pin (input)
USIL_DI pin (output)
USIL_DI pin (input)
IMTGMOD[2:0]
IMTG (write)
IMBSY
IMSTA[2:0]
TD[7:0]
RD[7:0]
IMIF
Start interrupt
End of transmission
interrupt
End of reception
interrupt
Receive
ACK interrupt
0x0
*
*
*
0x2
0x5
0x3
*
(1) Start condition
→
Data reception