Rainbow Electronics ATtiny28L - Manual (Page 49)

49
ATtiny28L/V
1062E–10/01
Reading the Fuse and Lock
Bits The algorithm for reading the Fuse and Lock bits is as follows (refer to “Programming
the Flash” for details on command loading):
A: Load Command “0000 0100”.
1. Set OE to “0”, and BS to “0”. The status of the Fuse bits can now be read at
DATA (“0” means programmed).
Bit 4 = INTCAP Fuse
Bit 3 = CKSEL3 Fuse
Bit 2 = CKSEL2 Fuse
Bit 1 = CKSEL1 Fuse
Bit 0 = CKSEL0 Fuse
2. Set BS to “1”. The status of the Lock bits can now be read at DATA (“0” means
programmed).
Bit 2: Lock Bit2
Bit 1: Lock Bit1
3. Set OE to “1”.
Reading the Signature Bytes
and Calibration Byte The algorithm for reading the signature bytes and the calibration byte is as follows (refer
to “Programming the Flash” for details on command and address loading):
A: Load Command “0000 1000”.
C: Load Address Low Byte ($00 - $02).
1. Set OE to “0”, and BS to “0”. The selected signature byte can now be read at
DATA.
C: Load Address Low Byte ($00).
1. Set OE to “0”, and BS to “1”. The calibration byte can now be read at DATA.
2. Set OE to “1”.
Figure 37. Programming the Flash Waveforms
$10 ADDR. HIGH ADDR. LOW DATA LOW DATA
XA1
XA0
BS
XTAL1
WR
RDY/BSY
RESET
OE
12V