ez80f91 ZiLOG Semiconductor, ez80f91 Datasheet - Page 221

• Manufacturer Part Number: ez80f91
• Description: Ez80 Acclaimplus!? Connectivity Assp Ez80f91 Assp
• Manufacturer: ZiLOG Semiconductor

I
PS027001-0707
2
C Serial I/O Interface
I
2
C General Characteristics
The Inter-Integrated Circuit (I
that operates in four modes:
•
•
•
•
The I
SDA are bidirectional lines connected to a positive supply voltage via an external pull-up
resistor. When the bus is free, both lines are High. The output stages of devices connected
to the bus must be configured as open-drain outputs. Data on the I
a rate of up to 100 kbps in STANDARD mode, or up to 400 kbps in FAST mode. One
clock pulse is generated for each data bit transferred.
Clocking Overview
If another device on the I
the I
determined by the device that generates the shortest High clock period. The Low period of
the clock is determined by the device that generates the longest Low clock period.
The Low period of the clock is stretched by a slave to slow down the bus master. The Low
period is also stretched for handshaking purposes. This result is accomplished after each
bit transfer or each byte transfer. The I
the IFLG bit in the I2C_CTL register is cleared to 0.
Bus Arbitration Overview
In MASTER mode, the I
a logic 1. If another device on the bus overrules and pulls the SDA signal Low, arbitration
is lost. If arbitration is lost during the transmission of a data byte or a Not Acknowledge
(NACK) bit, the I
an address, the I
the general call address.
MASTER TRANSMIT
MASTER RECEIVE
SLAVE TRANSMIT
SLAVE RECEIVE
2
2
C synchronizes its clock to the I
C interface consists of a Serial Clock (SCL) and Serial Data (SDA). Both SCL and
2
C switches to SLAVE mode so that it recognizes its own slave address or
2
C returns to an idle state. If arbitration is lost during the transmission of
2
2
C checks that each transmitted logic 1 appears on the I
C bus drives the clock line when the I
2
C) serial I/O bus is a two-wire communication interface
2
2
C bus clock. The High period of the clock is
C stretches the clock after each byte transfer until
2
Product Specification
C is in MASTER mode,
2
C bus are transferred at
I
2
C Serial I/O Interface
eZ80F91 ASSP
2
C bus as
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