Rainbow Electronics ATmega64L - Manual (Page 261)

261
ATmega16(L)
2466B–09/01
Programming the EEPROM The EEPROM is organized in pages, see Table 112 on page 257. 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 258 for details on
Command, Address and Data loading):
1. A: Load Command "0001 0001".
2. G: Load Address High Byte ($00 - $FF)
3. B: Load Address Low Byte ($00 - $FF)
4. C: Load Data ($00 - $FF)
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
131 for signal waveforms)
Figure 131. Programming the EEPROM Waveforms
Reading the Flash The algorithm for reading the Flash memory is as follows (refer to “Programming the
Flash” on page 258 for details on Command and Address loading):
1. A: Load Command "0000 0010".
2. G: Load Address High Byte ($00 - $FF)
3. B: Load Address Low Byte ($00 - $FF)
4. Set OE to "0", and BS1 to "0". The Flash word low byte can now be read at
DATA.
RDY/BSY
WR
OE
RESET +12V
PAGEL
BS2
$10 ADDR. HIGH
DATA
ADDR. LOW DATA ADDR. LOW DATA XX
XA1
XA0
BS1
XTAL1
XX
A G B C E B C E L
K