14 I
2
C (I2C)
S1C17M20/M21/M22/M23/M24/M25
Seiko Epson Corporation
14-1
TECHNICAL MANUAL (Rev. 1.0)
14 I
2
C (I2C)
14.1 Overview
The I2C is a subset of the I
2
C bus interface. The features of the I2C are listed below.
• Functions as an I
2
C bus master (single master) or a slave device.
• Supports standard mode (up to 100 kbit/s) and fast mode (up to 400 kbit/s).
• Supports 7-bit and 10-bit address modes.
• Supports clock stretching.
• Includes a baud rate generator for generating the clock in master mode.
• No clock source is required to run the I2C in slave mode, as it can run with the I
2
C bus signals only.
• Slave mode is capable of being operated in SLEEP mode allowing wake-up by an interrupt when an address
match is detected.
• Master mode supports automatic bus clear sending function.
• Can generate receive buffer full, transmit buffer empty, and other interrupts.
Figure 14.1.1 shows the I2C configuration.
Table 14.1.1 I2C Channel Configuration of S1C17M20/M21/M22/M23/M24/M25
Item
S1C17M20/M23
S1C17M21/M24
S1C17M22/M25
24-pin package
32-pin package
Number of channels
1 channel (Ch.0)
I2C Ch.n
Interrupt
control circuit
BYTEENDIE
GCIE
NACKIE
STOPIE
STARTIE
ERRIE
RBFIE
TBEIE
CLKSRC[1:0]
CLKDIV[1:0]
Transmit/receive
control circuit
Clock generator
Interrupt controller
DBRUN
MODEN
OADR[9:0]
CLK_I2Cn
Receive data buffer
RXD[7:0]
Transmit data buffer
TXD[7:0]
Slave mode
controller
Master mode
controller
Shift register
SDAn
Shift register
Baud rate
generator
OADR10
SFTRST
GCEN
MST
SDALOW
SCLLOW
BSY
TR
TXNACK
BRT[6:0]
TXSTART
TXSTOP
SCLn
SCLO
Inter
nal data
bu
s
BYTEENDIF
GCIF
NACKIF
STOPIF
STARTIF
ERRIF
RBFIF
TBEIF
V
SS
V
SS
Figure 14.1.1 I2C Configuration