em78f644nso28s ELAN Microelectronics Corp, em78f644nso28s Datasheet - Page 119

• Manufacturer Part Number: em78f644nso28s
• Description: Flash Series 8-bit Microcontroller
• Manufacturer: ELAN Microelectronics Corp

Product Specification (V1.0) 05.05.2010
(This specification is subject to change without further notice)
The possible data transfer formats for 10-bit Slave Address Mode are explained in the
following paragraphs:
6.8.2.1 Master-Transmitter Transmits to Slave-Receiver with a 10-bit Slave
When the Slave received the first byte after the START bit from the Master, each
Slave device will compare with the 7 bits of the first byte (11110XX) with their own
address and the 8th bit (R//W). If the R//W bit is “0”, the Slave will return an
Acknowledge A1. It is possible that more than one Slave devices will return the
Acknowledge A1. Then all Slave devices will continue to compare with the second
address (XXXXXXXX). If a Slave device has found a match, that particular Slave
device will be the only one to return an Acknowledge A2. The matched Slave device
will remain addressed by the Master until it receives a STOP condition or a repeated
START condition followed by a different Slave address.
6.8.2.2 Master-Receiver Reads from Slave-Transmitter with a 10-bit Slave
Up to, and including Acknowledge Bit A2, the procedure is the same as that described
above for Master-transmitter addressing a Slave receiver. After the Acknowledge A2,
a repeated START (Sr) condition takes place, followed by 7 bits Slave address
(11110XX) but the 8th bit R//W is “1”. The addressed Slave device will then return an
Acknowledge A3. If the repeated START (Sr) condition occurs and the 7 bits of the
first byte (11110XX) are received by the Slave device, all the Slave devices will
compare with their own address and test the 8th bit (R//W). However, none of the
Slave devices can return an Acknowledge because R//W=1.
Figure 6-20a Master-Transmitter Transmits to Slave-Receiver with a 10-Bit Slave Address
Figure 6-20b Master-Receiver Read Slave-Transmitter with a 10-Bit Slave Address
Address
Address
EM78F648/644/642/641/548/544/542/541N
8-Bit Microcontroller
• 109