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HT80C51 User Manual
Peripheral Modules – I2C Interface (SIO1)
Handshake Solutions
© Philips Electronics N.V. 2005
Page 73 of 132
STA FLAG
SDA LINE
SCL LINE
(3)
(1)
(1)
(2)
START CONDITION
(1) Unsuccessful attempt to send a Start condition
(2) SDA line released
(3) Successful attempt to send a Start condition; state 08H is entered.
[Figure 27] Recovering from a Bus Obstruction Caused by a Low Level on SDA
5.5.5.
Slave-only version
The description above covers the full featured version of the HT-I2C module with master and slave
modes. The slave-only version of the HT-I2C implements a subset of these features.
This means, the slave-only version covers the behaviour and features as described for the complete
version, but some features and pins are not implemented. It comprises
•
no master transmit mode
•
no master receiver mode
•
no baud rate generator
•
bits CR1, CR2, CR3 and STA in the SFR S1CON are reserved (0)
•
no clock input pin i2c_clk_i
5.5.6.
Application notes
An I2C byte-oriented system driver is described in application note AN435. Please visit
http://www.semiconductors.philips.com/products/all_appnotes.html