ATA6613 ATMEL Corporation, ATA6613 Datasheet - Page 293

• Manufacturer Part Number: ATA6613
• Description: Ata6613
• Manufacturer: ATMEL Corporation

6.23.7.3
6.23.7.4
6.23.7.5
6.23.7.6
6.23.7.7
9111C–AUTO–02/08
Performing a Page Write
Using the SPM Interrupt
Consideration While Updating BLS
Prevent Reading the RWW Section During Self-Programming
Setting the Boot Loader Lock Bits by SPM
To execute Page Write, set up the address in the Z-pointer, write “X0000101” to SPMCSR and
execute SPM within four clock cycles after writing SPMCSR. The data in R1 and R0 is ignored.
The page address must be written to PCPAGE. Other bits in the Z-pointer must be written to
zero during this operation.
If the SPM interrupt is enabled, the SPM interrupt will generate a constant interrupt when the
SELFPRGEN bit in SPMCSR is cleared. This means that the interrupt can be used instead of
polling the SPMCSR Register in software. When using the SPM interrupt, the Interrupt Vectors
should be moved to the BLS section to avoid that an interrupt is accessing the RWW section
when it is blocked for reading. How to move the interrupts is described in
page
Special care must be taken if the user allows the Boot Loader section to be updated by leaving
Boot Lock bit11 unprogrammed. An accidental write to the Boot Loader itself can corrupt the
entire Boot Loader, and further software updates might be impossible. If it is not necessary to
change the Boot Loader software itself, it is recommended to program the Boot Lock bit11 to
protect the Boot Loader software from any internal software changes.
During Self-Programming (either Page Erase or Page Write), the RWW section is always
blocked for reading. The user software itself must prevent that this section is addressed during
the self programming operation. The RWWSB in the SPMCSR will be set as long as the RWW
section is busy. During Self-Programming the Interrupt Vector table should be moved to the BLS
as described in
addressing the RWW section after the programming is completed, the user software must clear
the RWWSB by writing the RWWSRE. See
on page 296
To set the Boot Loader Lock bits, write the desired data to R0, write “X0001001” to SPMCSR
and execute SPM within four clock cycles after writing SPMCSR. The only accessible Lock bits
are the Boot Lock bits that may prevent the Application and Boot Loader section from any soft-
ware update by the MCU.
See
Boot Loader bits affect the Flash access.
• Page Write to the RWW section: The NRWW section can be read during the Page Write.
• Page Write to the NRWW section: The CPU is halted during the operation.
Table 6-103 on page 288
74.
Bit
R0
for an example.
“Watchdog Timer” on page
7
1
6
1
and
BLB12
Table 6-104 on page 288
5
BLB11
“Simple Assembly Code Example for a Boot Loader”
4
74, or the interrupts must be disabled. Before
BLB02
3
ATA6612/ATA6613
BLB01
for how the different settings of the
2
1
1
“Watchdog Timer” on
0
1
293