Rainbow Electronics AT86RF401 - Manual (Page 14)

14
AT86RF401
1424D–RKE–09/02
Serial Programming
Algorithm
Refer to Figure 4 (page 15), Figure 5 (page 16) and Figure 6 (page 17). To program and
verify the AT86RF401 in the serial programming mode, the following sequence is
recommended.
Power-up Sequence:
1. Apply power between VDD and GND while RESETB and SCK are set to “0”. If a
crystal is not connected across pins XTAL and XTALB, apply a clock signal to the
XTAL pin. If the programmer can not guarantee that SCK is held low during
power-up, RESETB must be given a positive pulse after SCK has been set to “0”.
2. Wait for at least 20 ms and enable serial programming by sending the Program-
ming Enable instruction to pin SDI. This must occur prior to any program/erase
operations.
3. If a chip erase is performed, wait 4 ms, give RESETB a positive pulse and start
over again from Step 2.
4. The array is programmed one byte at a time by supplying the address and data
together with the appropriate Write instruction. The memory location is first auto-
matically erased before new data is written. The next byte can be written after
4 ms.
5. Any memory location can be verified by using the Read instruction, which
returns the content at the selected address at serial output SDO.
6. At the end of the programming session, RESETB must be set high to commence
normal operation.