at32uc3b0512-z2ues ATMEL Corporation, at32uc3b0512-z2ues Datasheet - Page 123

• Manufacturer Part Number: at32uc3b0512-z2ues
• Description: 32-bit Avr Microcontroller
• Manufacturer: ATMEL Corporation

14.4.5
14.4.6
32059J–12/2010
Quick Page Read
Write page buffer operations
The flash controller supports flash blocks with up to 2^21 word addresses, as displayed in
14-1. Reading the memory space between address pw and 2^21-1 returns an undefined result.
The User page is permanently mapped to word address 2^21.
Table 14-1.
Figure 14-1. Memory map for the Flash memories
A dedicated command, Quick Page Read (QPR), is provided to read all words in an addressed
page. All bits in all words in this page are AND’ed together, returning a 1-bit result. This result is
placed in the Quick Page Read Result (QPRR) bit in Flash Status Register (FSR). The QPR
command is useful to check that a page is in an erased state. The QPR instruction is much
faster than performing the erased-page check using a regular software subroutine.
The internal memory area reserved for the embedded flash can also be written through a write-
only page buffer. The page buffer is addressed only by the address bits required to address w
words (since the page buffer is word addressable) and thus wrap around within the internal
memory area address space and appear to be repeated within it.
When writing to the page buffer, the PAGEN field in the
updated with the page number corresponding to page address of the latest word written into the
page buffer.
Memory type
Main array
User
User page addresses
2 ^ 2 1 + 1 2 8
A ll a d d r e s s e s a r e w o r d a d d r e s s e s
Start address, byte sized
0
2^23 = 8388608
p w - 1
2 ^ 2 1
p w
F la s h w it h
e x t r a p a g e
0
U n u s e d
U s e r p a g e
Size
pw words = 4pw bytes
128 words = 512 bytes
Flash Command register (
AT32UC3B
FCMD) is
Figure
123