HD6433694 Datasheet, PDF (298/432 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Tiny Series

17.4.8 Acknowledge Polling
Acknowledge polling feature is used to show if the EEPROM is in an internally-timed write cycle
or not. This feature is initiated by the input of the 8-bit slave address + R/W code following the
start condition during an internally-timed write cycle. Acknowledge polling will operate R/W
code = "0". The ninth acknowledgement judges if the EEPROM is an internally-timed write cycle
or not. Acknowledgement "1" shows the EEPROM is in a internally-timed write cycle and
acknowledgement "0" shows the internally-timed write cycle has been completed. The
acknowledge polling starts to function after a write data is input, i.e., when the stop condition is
input.
17.4.9 Read Operation
There are three read operations; current address read, random address read, and sequential read.
Read operations are initiated in the same way as write operations with the exception of R/W = 1.
1. Current Address Read
The internal address counter maintains the (n+1) address that is made by the last address (n)
accessed during the last read or write operation, with incremented by one. Current address
read accesses the (n+1) address kept by the internal address counter.
After receiving in the order of a start condition and the slave address + R/W code (R/W = 1),
the EEPROM outputs the 1-byte data of the (n+1) address from the most significant bit
following acknowledgement "0". If the EEPROM receives in the order of acknowledgement
"1" and a following stop condition, the EEPROM stops the read operation and is turned to a
standby state.
In case the EEPROM has accessed the last address H'01FF at previous read operation, the
current address will roll over and returns to zero address. In case the EEPROM has accessed
the last address of the page at previous write operation, the current address will roll over within
page addressing and returns to the first address in the same page.
The current address is valid while power is on. The current address after power on will be
undefined. After power is turned on, define the address by the random address read operation
described below is necessary.
The current address read operation is shown in figure 17.5.
Rev. 4.00, 03/04, page 270 of 400