HD64F3694HV Datasheet, PDF (315/452 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Tiny Series

Section 17 EEPROM
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.
SCL
1 2 34 5 6 7891
89
SDA
D7
D0
Slave address
Start
condition
[Legend]
R/W: R/W code (0 is for a write and 1 is for a read)
ACK: acknowledge
R/W ACK
Read Data
ACK
Stop
conditon
Figure 17.5 Current Address Read Operation
Rev.5.00 Nov. 02, 2005 Page 285 of 418
REJ09B0028-0500