AT90CAN128-15AZ Datasheet, PDF (344/431 Pages) ATMEL Corporation – 8-bit Microcontroller with 32K/64K/128K Bytes of ISP Flash and CAN Controller

25.6.5
Programming the EEPROM
The EEPROM is organized in pages, see Table 25-12 on page 340. When programming the
EEPROM, the program data is latched into a page buffer. This allows one page of data to be
programmed simultaneously. The programming algorithm for the EEPROM data memory is as
follows (refer to “Programming the Flash” on page 341 for details on Command, Address and
Data loading):
1. A: Load Command “0001 0001”.
2. G: Load Address High Byte (0x00 - 0xFF).
3. B: Load Address Low Byte (0x00 - 0xFF).
4. C: Load Data (0x00 - 0xFF).
5. E: Latch data (give PAGEL a positive pulse).
K: Repeat 3 through 5 until the entire buffer is filled.
L: Program EEPROM page
1. Set BS1 to “0”.
2. Give WR a negative pulse. This starts programming of the EEPROM page. RDY/BSY
goes low.
3. Wait until to RDY/BSY goes high before programming the next page (See Figure 25-4
for signal waveforms).
Figure 25-4. Programming the EEPROM Waveforms
K
DATA
XA1
XA0
BS1
XTAL1
WR
RDY/BSY
RESET +12V
OE
PAGEL
BS2
A
G
B
C
E
B
C
E
L
0x11
ADDR. HIGH ADDR. LOW
DATA
XX
ADDR. LOW
DATA
XX
25.6.6
Reading the Flash
The algorithm for reading the Flash memory is as follows (refer to “Programming the Flash” on
page 341 for details on Command and Address loading):
1. A: Load Command “0000 0010”.
2. G: Load Address High Byte (0x00 - 0xFF).
3. B: Load Address Low Byte (0x00 - 0xFF).
4. Set OE to “0”, and BS1 to “0”. The Flash word low byte can now be read at DATA.
5. Set BS1 to “1”. The Flash word high byte can now be read at DATA.
6. Set OE to “1”.
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