Rainbow Electronics AT90S2313 - Manual (Page 65)

65
AT90S2313
0839I–AVR–06/02
Reading the Flash The algorithm for reading the Flash memory is as follows (refer to “Programming the
Flash” for details on command and address loading):
1. A: Load Command “0000 0010”.
2. B: Load Address High Byte ($00 - $03).
3. C: Load Address Low Byte ($00 - $FF).
4. Set OE to “0”, and BS to “0”. The Flash word low byte can now be read at DATA.
5. Set BS to “1”. The Flash word high byte can now be read from DATA.
6. Set OE to “1”.
Programming the EEPROM The programming algorithm for the EEPROM data memory is as follows (refer to “Pro-
gramming the Flash” for details on command, address and data loading):
1. A: Load Command “0001 0001”.
2. C: Load Address Low Byte ($00 - $7F).
3. D: Load Data Low Byte ($00 - $FF).
4. E: Write Data Low Byte.
Reading the EEPROM The algorithm for reading the EEPROM memory is as follows (refer to “Programming the
Flash” for details on command and address loading):
1. A: Load Command “0000 0011”.
2. C: Load Address Low Byte ($00 - $7F).
3. Set OE to “0”, and BS to “0”. The EEPROM data byte can now be read at DATA.
4. Set OE to “1”.
Programming the Fuse Bits The algorithm for programming the Fuse bits is as follows (refer to “Programming the
Flash” for details on command and data loading):
1. A: Load Command “0100 0000”.
2. D: Load Data Low Byte. Bit n = “0” programs and bit n = “1” erases the Fuse bit.
Bit 5 = SPIEN Fuse bit.
Bit 0 = FSTRT Fuse bit.
Bit 7 - 6, 4 - 1 = “1”. These bits are reserved and should be left unprogrammed (“1”).
3. Give WR a t
WLWH_PFB
wide negative pulse to execute the programming; t
WLWH_PFB
is
found in Table 26. Programming the Fuse bits does not generate any activity on
the RDY/BSY pin.
Programming the Lock Bits The algorithm for programming the Lock bits is as follows (refer to “Programming the
Flash” on page 63 for details on command and data loading):
1. A: Load Command “0010 0000”.
2. D: Load Data Low Byte. Bit n = “0” programs the Lock bit.
Bit 2 = Lock Bit2
Bit 1 = Lock Bit1
Bit 7 - 3, 0 = “1”. These bits are reserved and should be left unprogrammed (“1”).
3. E: Write Data Low Byte.
The Lock bits can only be cleared by executing Chip Erase.