atmega323l ATMEL Corporation, atmega323l Datasheet - Page 209

• Manufacturer Part Number: atmega323l
• Description: Atmega323 8-bit Avr Microcontroller With 32k Bytes Of In-system Programmable Flash
• Manufacturer: ATMEL Corporation

Virtual Flash Page Read
Register
Programming algorithm
Entering programming mode
Leaving Programming Mode
1457G–AVR–09/03
The Virtual Flash Page Read Register is a virtual scan chain with length equal to the
number of bits in one Flash page plus eight, 1,032 in total. Internally the Shift Register is
8-bit, and the data are automatically transferred from the Flash data page byte-by-byte.
The first eight cycles are used to transfer the first byte to the internal Shift Register, and
the bits that are shifted out during these eight cycles should be ignored. Following this
initialization, data are shifted out starting with the LSB of the instruction with page
address 0 and ending with the MSB of the instruction with page address 3F. This pro-
vides an efficient way to read one full Flash page to verify programming.
Figure 105. Virtual Flash Page Read Register
All references below of type “1a”, “1b”, and so on, refer to Table 71.
1. Enter JTAG instruction AVR_RESET and shift 1 in the Reset Register.
2. Enter instruction PROG_ENABLE and shift 1010_0011_0111_0000 in the Pro-
1. Enter JTAG instruction PROG_COMMANDS.
2. Disable all programming instructions by using no operation instruction 11a.
3. Enter instruction PROG_ENABLE and shift 0000_0000_0000_0000 in the pro-
4. Enter JTAG instruction AVR_RESET and shift 0 in the Reset Register.
If PROG_ENABLE instruction is not followed by the AVR_RESET instruction, the follow-
ing algorithm should be used:
1. Enter JTAG instruction PROG_COMMANDS.
2. Disable all programming instructions by using no operation instruction 11a.
3. Enter instruction PROG_ENABLE and shift 0000_0000_0000_0000 in the Pro-
4. Enter instruction PROG_ENABLE and shift 0000_0000_0000_0000 in the Pro-
5. Wait until the selected Oscillator has started before applying more commands.
gramming Enable Register.
gramming Enable Register.
gramming Enable Register.
gramming Enable Register.
TDO
TDI
D
A
T
A
machine
State
STROBES
ADDRESS
EEPROM
Lock Bits
Fuses
Flash
ATmega323(L)
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