Datasheet

ATmega32A
 2018 Microchip Technology Inc. Data Sheet Complete DS40002072A-page 264
27.7.5 Programming the EEPROM
The EEPROM is organized in pages, see Table 27-6 on page 259. When programming the EEPROM, the program
data is latched into a page buffer. This allows one page of data to be programmed simultaneously. The program-
ming algorithm for the EEPROM data memory is as follows (refer to “Programming the Flash” on page 262 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 27-4 for signal
waveforms)
Figure 27-4. Programming the EEPROM Waveforms
27.7.6 Reading the Flash
The algorithm for reading the Flash memory is as follows (refer to “Programming the Flash” on page 262 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.
5. Set BS1 to “1”. The Flash word high byte can now be read at DATA.
RDY/BSY
WR
OE
RESET +12V
PAGEL
BS2
0x11 ADDR. HIGH
DATA
ADDR. LOW DATA ADDR. LOW DATA XX
XA1
XA0
BS1
XTAL1
XX
AGB CEBCE L
K