Section 25 I C Bus Interface (Iic); Overview; Features - Renesas Hitachi H8S/2194 Series Hardware Manual

Section 25 I
25.1

Overview

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The I C bus interface conforms to and provides a subset of the Philips I
interface functions. The register configuration that controls the I
Philips configuration, however.
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Each I C bus interface channel uses only one data line (SDA) and one clock line (SCL) to
transfer data, saving board and connector space.
25.1.1

Features

• Selection of addressing format or non-addressing format
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— I C bus format: addressing format with acknowledge bit, for master/slave operation
— Serial format: non-addressing format without acknowledge bit, for master operation only
• Conforms to Philips I
• Two ways of setting slave address (I
• Start and stop conditions generated automatically in master mode (I
• Selection of acknowledge output levels when receiving (I
• Automatic loading of acknowledge bit when transmitting (I
• Wait function in master mode (I
— A wait can be inserted by driving the SCL pin low after data transfer, excluding
acknowledgement. The wait can be cleared by clearing the interrupt flag.
• Wait function in slave mode (I
— A wait request can be generated by driving the SCL pin low after data transfer, excluding
acknowledgement. The wait request is cleared when the next transfer becomes possible.
• Three interrupt sources
— Data transfer end (including transmission mode transition with I
reception after loss of master arbitration)
— Address match: when any slave address matches or the general call address is received in
slave receive mode (I
— Stop condition detection
• Selection of 16 internal clocks (in master mode)
• Direct bus drive (with SCL and SDA pins)
— Two pins-P24/SCL and P23/SDA- (normally CMOS pins) function as NMOS-only
outputs when the bus drive function is selected.
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C Bus Interface (IIC)
2 2
C bus interface (I C bus format)
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C bus format)
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C bus format)
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C bus format)
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C bus format)
2
C bus (inter-IC bus)
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C bus differs partly from the
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C bus format)
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C bus format)
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C bus format)
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C bus format and address
Rev. 2.0, 11/00, page 517 of 1037