ATA5771_09 ATMEL [ATMEL Corporation], ATA5771_09 Datasheet - Page 222

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ATA5771_09

Manufacturer Part Number
ATA5771_09
Description
Microcontroller with UHF ASK/FSK Transmitter
Manufacturer
ATMEL [ATMEL Corporation]
Datasheet
21.6.1
7701C–AVR–12/08
Serial Programming Algorithm
When writing serial data to the ATtiny24/44/84, data is clocked on the rising edge of SCK.
When reading data from the ATtiny24/44/84, data is clocked on the falling edge of SCK. See
Figure 22-3
To program and verify the ATtiny24/44/84 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. A: 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):
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 5 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 3 MSB of
the address. If polling (RDY/BSY) is not used, the user must wait at least t
issuing the next page. (See
ming interface before the 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 (RDY/BSY) is not used, the
user must wait at least t
page
B: The EEPROM array is programmed one page at a time. The Memory page is loaded
one byte at a time by supplying the 2 LSB of the address and data together with the Load
EEPROM Memory Page instruction. The EEPROM Memory Page is stored by loading
the Write EEPROM Memory Page Instruction with the 4 MSB of the address. When using
EEPROM page access only byte locations loaded with the Load EEPROM Memory Page
instruction is altered. The remaining locations remain unchanged. If polling (RDY/BSY) is
not used, the used must wait at least t
21-10 on page
programmed.
tent at the selected address at serial output MISO.
operation.
Set RESET to “1”.
Turn V
170.) In a chip erased device, no 0xFFs in the data file(s) need to be programmed.
CC
and
power off.
Figure 22-4
170). In a chip erased device, no 0xFF in the data file(s) need to be
CC
WD_EEPROM
for timing details.
and GND while RESET and SCK are set to “0”. In some sys-
Table 21-10 on page
before issuing the next byte. (See
WD_EEPROM
before issuing the next page (See
170.) Accessing the serial program-
Table
ATtiny24/44/84
21-11):
Table 21-10 on
WD_FLASH
before
Table
169

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