Class _fla: Flash memory

This class is used by:

• ATtiny24/44/84 : flash0
• ATtiny25/45/85 : flash0
• ATmega48A/PA/88A/PA/168A/PA/328/P : flash0
• ATmega16U4/32U4 : flash0

Actions

hw( read, ... ) - Read one byte at given memory address:

uint8_t byte = hw( read, flash0, addr ); // Read byte at address addr

hw( read_bytes, ... ) - Copy n bytes from Flash memory to RAM:

uint8_t dst[10];
uint8_t count = sizeof(dst);
hw( read_bytes, flash0, dst, addr, count ); // Copy count bytes from Flash address addr to dst

hw( load_buffer, ... ), hw( erase_page, ... ), hw( write_page, ... ) - Write data to Flash memory

Writing into the memory requires a special procedure:

1. Load a page buffer with the content to be written. HW_DEVICE_FLASH_PAGE_SIZE gives the page buffer size.
2. Erase the page to be programmed.
3. Program the page with the content of the page buffer.

Steps 1 & 2 can be done in any order.

uint8_t page[HW_DEVICE_FLASH_PAGE_SIZE] ;
intptr_t zpage = address & ~(HW_DEVICE_FLASH_PAGE_SIZE-1) ;
 
hw( load_buffer, flash0, page );  // Store data into the memory page buffer
hw( erase_page, flash0, zpage );  // Erase memory page
hw( write_page, flash0, zpage );  // Program memory page with page buffer content

Registers

Harware registers:

• csr

Logical registers:

• spmie
• rwwsb
• sigrd
• rwwsre
• blbset
• pgwrt
• pgers
• spmen