ATMEga64L ATMEL Corporation, ATMEga64L Datasheet - Page 321

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

Virtual Flash Page Load
Register
Virtual Flash Page Read
Register
2490G–AVR–03/04
The Virtual Flash Page Load Register is a virtual scan chain with length equal to the
number of bits in one Flash page. Internally the Shift Register is 8-bit, and the data are
automatically transferred to the Flash page buffer byte-by-byte. Shift in all instruction
words in the page, starting with the LSB of the first instruction in the page and ending
with the MSB of the last instruction in the page. This provides an efficient way to load the
entire Flash page buffer before executing Page Write.
Figure 153. Virtual Flash Page Load Register
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. 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 first instruction in the page and ending
with the MSB of the last instruction in the page. This provides an efficient way to read
one full Flash page to verify programming.
TDO
TDI
D
A
T
A
Machine
State
STROBES
ADDRESS
EEPROM
Lock Bits
Fuses
Flash
ATmega64(L)
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