at90ls8535-8mi ATMEL Corporation, at90ls8535-8mi Datasheet - Page 101

• Manufacturer Part Number: at90ls8535-8mi
• Description: 8-bit Microcontroller With 8k Bytes In-system Programmable Flash
• Manufacturer: ATMEL Corporation

Data Polling EEPROM
Data Polling Flash
1041H–11/01
4. If a Chip Erase is performed (must be done to erase the Flash), wait t
5. The Flash or EEPROM array is programmed one byte at a time by supplying the
6. Any memory location can be verified by using the Read instruction that returns
7. At the end of the programming session, RESET can be set high to commence
8. Power-off sequence (if needed):
When a byte is being programmed into the EEPROM, reading the address location
being programmed will give the value P1 until the auto-erase is finished and then the
value P2. See Table 41 for P1 and P2 values.
At the time the device is ready for a new EEPROM byte, the programmed value will read
correctly. This is used to determine when the next byte can be written. This will not work
for the values P1 and P2, so when programming these values, the user will have to wait
for at least the prescribed time t
45 for t
ming of addresses that are meant to contain $FF can be skipped. This does not apply if
the EEPROM is reprogrammed without first chip-erasing the device.
Table 41. Read Back Value during EEPROM Polling
When a byte is being programmed into the Flash, reading the address location being
programmed will give the value $FF. At the time the device is ready for a new byte, the
programmed value will read correctly. This is used to determine when the next byte can
be written. This will not work for the value $FF, so when programming this value, the
user will have to wait for at least t
erased device contains $FF in all locations, programming of addresses that are meant
to contain $FF can be skipped.
Figure 72. Serial Programming Waveforms
SERIAL DATA OUTPUT
SERIAL CLOCK INPUT
Part
AT90S/LS8535
SERIAL DATA INPUT
after the instruction, give RESET a positive pulse and start over from step 2. See
Table 44 for t
address and data together with the appropriate Write instruction. An EEPROM
memory location is first automatically erased before new data is written. Use
Data Polling to detect when the next byte in the Flash or EEPROM can be writ-
ten. If polling is not used, wait t
See Table 45 for t
needs to be programmed.
the content at the selected address at the serial output MISO (PB6) pin.
normal operation.
Set XTAL1 to “0” (if a crystal is not used).
Set RESET to “1”.
Turn V
WD_PROG
PB5(MOSI)
PB6(MISO)
PB7(SCK)
CC
power off.
value. As a chip-erased device contains $FF in all locations, program-
WD_ERASE
WD_PROG
MSB
MSB
value.
value. In an erased device, no $FFs in the data file(s)
WD_PROG
WD_PROG
WD_PROG
before programming the next byte. See Table
before programming the next byte. As a chip-
before transmitting the next instruction.
P1
$00
AT90S/LS8535
P2
$FF
WD_ERASE
LSB
LSB
101