atmega32c1 ATMEL Corporation, atmega32c1 Datasheet - Page 306

• Manufacturer Part Number: atmega32c1
• Description: Atmega32m1 Automotive 8-bit Avr Microcontroller With 32k/64k Bytes In-system Programmable Flash
• Manufacturer: ATMEL Corporation

24.9.2
24.9.3
306
ATmega32/64/M1/C1
Data Polling Flash
Data Polling EEPROM
When reading data from the ATmega32/64/M1/C1, data is clocked on the falling edge of SCK.
See
To program and verify the ATmega32/64/M1/C1 in the serial programming mode, the following
sequence is recommended (See four byte instruction formats in
1. Power-up sequence:
2. Wait for at least 20 ms and enable serial programming by sending the Programming
3. The serial programming instructions will not work if the communication is out of synchro-
4. The Flash is programmed one page at a time. The memory page is loaded one byte at a
5. The EEPROM array is programmed one byte at a time by supplying the address and
6. Any memory location can be verified by using the Read instruction which returns the con-
7. At the end of the programming session, RESET can be set high to commence normal
8. Power-off sequence (if needed):
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 writ-
ten. 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
a chip-erased device contains 0xFF in all locations, programming of addresses that are meant to
contain 0xFF, can be skipped. See
When a new byte has been written and is being programmed into EEPROM, reading the
address location being programmed will give the value 0xFF. At the time the device is ready for
Apply power between V
tems, the programmer can not guarantee that SCK is held low during power-up. In this
case, RESET must be given a positive pulse of at least two CPU clock cycles duration
after SCK has been set to “0”.
Enable serial instruction to pin MOSI.
nization. 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 Programming Enable command.
time by supplying the 6 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 a given address. The Program Memory
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
next page. (See
Flash write operation completes can result in incorrect programming.
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
device, no 0xFFs in the data file(s) need to be programmed.
tent at the selected address at serial output MISO.
operation.
Set RESET to “1”.
Turn V
Figure 24-11
CC
WD_EEPROM
power off.
for timing details.
Table
before issuing the next byte. (See
CC
24-16.) Accessing the serial programming interface before the
and GND while RESET and SCK are set to “0”. In some sys-
Table 24-16
WD_FLASH
for t
WD_FLASH
before programming the next page. As
Table
value.
Table
WD_FLASH
24-16.) In a chip erased
24-17):
before issuing the
7647A–AVR–02/08