Datasheet

299
SAM3X / SAM3A [DATASHEET]
Atmel-11057C-ATARM-SAM3X-SAM3A-Datasheet_23-Mar-15
By using the WP command, a page can be programmed in several steps if it has been erased before (see Figure
18-6).
Figure 18-6. Example of Partial Page Programming
The Partial Programming mode works only with 128-bit (or higher) boundaries. It cannot be used with boundaries
lower than 128 bits (8, 16 or 32-bit for example).
18.4.3.3 Erase Commands
Erase commands are allowed only on unlocked regions.
The erase sequence is:
 Erase starts as soon as one of the erase commands and the FARG field are written in the Flash Command
Register.
 When the programming completes, the FRDY bit in the Flash Programming Status Register (EEFC_FSR)
rises. If an interrupt has been enabled by setting the FRDY bit in EEFC_FMR, the interrupt line of the NVIC
is activated.
Two errors can be detected in the EEFC_FSR register after a programming sequence:
 a Command Error: a bad keyword has been written in the EEFC_FCR register.
 a Lock Error: at least one page to be erased belongs to a locked region. The erase command has been
refused, no page has been erased. A command must be run previously to unlock the corresponding region.
18.4.3.4 Lock Bit Protection
Lock bits are associated with several pages in the embedded Flash memory plane. This defines lock regions in the
embedded Flash memory plane. They prevent writing/erasing protected pages.
The lock sequence is:
 The Set Lock command (SLB) and a page number to be protected are written in the Flash Command
Register.
 When the locking completes, the FRDY bit in the Flash Programming Status Register (EEFC_FSR) rises. If
an interrupt has been enabled by setting the FRDY bit in EEFC_FMR, the interrupt line of the NVIC is
activated.
 If the lock bit number is greater than the total number of lock bits, then the command has no effect. The
result of the SLB command can be checked running a GLB (Get Lock Bit) command.
Erase All Flash Programming of the second part of Page Y Programming of the third part of Page Y
32-bit wide 32-bit wide 32-bit wide
X words
FF FF FF FF
FF FF FF FF
FF FF FF FF
FF FF FF FF
FF FF FF FF
FF FF FF FF
FF FF FF FF
FF FF FF FF
FF FF FF FF
FF FF FF FF
FF FF FF FF
FF FF FF FF
...
CA FE CA FE
CA FE CA FE
CA FE CA FE
FF FF FF FF
FF FF FF FF
FF FF FF FF
FF FF FF FF
FF FF FF FF
FF FF FF FF
FF FF FF FF
FF FF FF FF
FF FF FF FF
CA FE CA FE
CA FE CA FE
CA FE CA FE
DE CA DE CA
DE CA DE CA
DE CA DE CA
FF FF FF FF
FF FF FF FF
FF FF FF FF
FF FF FF FF
FF FF FF FF
FF FF FF FF
Step 1. Step 2. Step 3.
...
...
...
...
...
...
...
...
...
...
...
X words
X words
X words
So Page Y erased