Atmega4hvd/8hvd – Rainbow Electronics ATmega8HVD User Manual
Page 128

128
8052B–AVR–09/08
ATmega4HVD/8HVD
This bit enables the SPM instruction for the next four clock cycles. If written to one together
with either CTPB, RFLB, PGWRT, or PGERS, the following SPM instruction will have a spe-
cial meaning, see description above. If only SPMEN is written, the following SPM instruction
will store the value in R1:R0 in the temporary page buffer addressed by the Z-pointer. The
LSB of the Z-pointer is ignored. The SPMEN bit will auto-clear upon completion of an SPM
instruction, or if no SPM instruction is executed within four clock cycles. During Page Erase
and Page Write, the SPMEN bit remains high until the operation is completed.
Writing any other combination than “10001”, “01001”, “00101”, “00011” or “00001” in the lower
five bits will have no effect.