ATmega8U2/16U2/32U2
Table 25-16. Serial Programming Instruction Set (Continued)
Instruction Format
Instruction
Byte 1
Byte 2
Byte 3
Byte4
Operation
0101 0000 0000 1000 xxxx xxxx oooo oooo Read Extended Fuse bits. “0” = pro-
grammed, “1” = unprogrammed. See
Read Extended Fuse Bits
Read Calibration Byte
Poll RDY/BSY
Table 25-3 on page 247 for details.
0011 1000 000x xxxx 0000 0000 oooo oooo Read Calibration Byte
1111 0000 0000 0000 xxxx xxxx xxxx xxxo If o = “1”, a programming operation is
still busy. Wait until this bit returns to
“0” before applying another command.
Note:
a = address high bits, b = address low bits, c = address extended bits, H = 0 - Low byte, 1 - High Byte, o = data out, i = data in,
x = don’t care
25.9.2
Serial Programming Characteristics
For characteristics of the Serial Programming module see “SPI Timing Characteristics” on page
269.
263
7799D–AVR–11/10
ATMEL [ ATMEL ]
