ATMEga64L ATMEL Corporation, ATMEga64L Datasheet - Page 308

• Manufacturer Part Number: ATMEga64L
• Description: 8-bit AVR Microcontroller with 64K Bytes In-System Programmable Flash
• Manufacturer: ATMEL Corporation

Data Polling Flash
308
ATmega64(L)
2. Wait for at least 20 ms and enable SPI Serial Programming by sending the Pro-
3. The SPI Serial Programming instructions will not work if the communication is
4. The Flash is programmed one page at a time. The Page size is found in Table
5. The EEPROM array is programmed one byte at a time by supplying the address
6. Any memory location can be verified by using the Read instruction which returns
7. At the end of the programming session, RESET can be set high to commence
8. Power-off sequence (if needed):
Note:
When a page is being programmed into the Flash, reading an address location within
the page being programmed will give the value 0xFF. At the time the device is ready for
a new page, the programmed value will read correctly. This is used to determine when
the next page can be written. Note that the entire page is written simultaneously and any
address within the page can be used for polling. Data polling of the Flash will not work
for the value 0xFF, so when programming this value, the user will have to wait for at
least t
0xFF in all locations, programming of addresses that are meant to contain 0xFF, can be
skipped. See Table 129 for t
CPU clock cycles duration after SCK has been set to “0”.
As an alternative to using the RESET signal, PEN can be held low during Power-
on Reset while SCK is set to “0”. In this case, only the PEN value at Power-on
Reset is important. If the programmer cannot guarantee that SCK is held low
during Power-up, the PEN method cannot be used. The device must be powered
down in order to commence normal operation when using this method.
gramming Enable serial instruction to pin MOSI.
out of synchronization. When in sync. the second byte (0x53), will echo back
when issuing the third byte of the Programming Enable instruction. Whether the
echo is correct or not, all four bytes of the instruction must be transmitted. If the
0x53 did not echo back, give RESET a positive pulse and issue a new Program-
ming Enable command.
125 on page 296. The memory page is loaded one byte at a time by supplying
the 7 LSB of the address and data together with the Load Program Memory
Page instruction. To ensure correct loading of the page, the data low byte must
be loaded before data high byte is applied for given address. The Program Mem-
ory Page is stored by loading the Write Program Memory Page instruction with
the 8 MSB of the address. If polling is not used, the user must wait at least
t
Serial Programming interface before the Flash write operation completes can
result in incorrect programming.
and data together with the appropriate Write instruction. An EEPROM memory
location is first automatically erased before new data is written. If polling is not
used, the user must wait at least t
Table 129).
the content at the selected address at serial output MISO.
normal operation.
Set RESET to “1”.
Turn V
WD_FLASH
WD_FLASH
If other commands that polling (read) are applied before any write operation (FLASH,
EEPROM, Lock bits, Fuses) is completed, may result in incorrect programming.
CC
power off.
before issuing the next page. (See Table 129). Accessing the SPI
before programming the next page. As a chip -erased device contains
WD_FLASH
value.
WD_EEPROM
before issuing the next byte. (See
2490G–AVR–03/04