Z8F1601 Datasheet, PDF (134/246 Pages) Zilog, Inc. – Z8 Encore Microcontrollers with Flash Memory and 10-Bit A/D Converter

Z8F640x/Z8F480x/Z8F320x/Z8F240x/Z8F160x
Z8 Encore!^®
116
1. Software writes the I²C Data register with a 7-bit slave address followed by a 1 (read).
2. Software asserts the START bit of the I²C Control register.
3. Software asserts the NAK bit of the I²C Control register so that after the first byte of
data has been read by the I²C Controller, a Not Acknowledge is sent to the I²C slave.
4. The I²C Controller sends the START condition.
5. The I²C Controller sends the address and read bit by the SDA signal.
6. The I²C slave sends an Acknowledge by pulling the SDA signal Low during the next
high period of SCL.
7. The I²C Controller reads the first byte of data from the I²C slave.
8. The I²C Controller asserts the Receive interrupt.
9. Software responds by reading the I²C Data register.
10. The I²C Controller sends a NAK to the I²C slave.
11. A NAK interrupt is generated by the I²C Controller.
12. Software responds by setting the STOP bit of the I²C Control register.
13. A STOP condition is sent to the I²C slave.
Reading a Transaction with a 10-Bit Address
Figure 82 illustrates the receive format for a 10-bit addressed slave. The shaded regions
indicate data transferred from the I²C Controller to slaves and unshaded regions indicate
data transferred from the slaves to the I²C Controller.
S Slave Address W=0 A Slave address A S Slave Address R=1 A Data A Data A P
1st 7 bits
2nd Byte
1st 7 bits
Figure 82. Receive Data Format for a 10-Bit Addressed Slave
The first seven bits transmitted in the first byte are 11110XX. The two bits XX are the two
most-significant bits of the 10-bit address. The lowest bit of the first byte transferred is the
write signal.
The data transfer format for a receive operation on a 10-bit addressed slave is as follows:
1. Software writes an address 11110B followed by the two address bits and a 0 (write).
2. Software asserts the START bit of the I²C Control register.
3. The I²C Controller sends the Start condition.
PS017609-0803
I2C Controller