AT32UC3L0256 Atmel Corporation, AT32UC3L0256 Datasheet - Page 82

• Manufacturer Part Number: AT32UC3L0256
• Manufacturer: Atmel Corporation

Specifications of AT32UC3L0256

• Flash (kbytes): 256 Kbytes
• Pin Count: 48
• Max. Operating Frequency: 50 MHz
• Cpu: 32-bit AVR
• # Of Touch Channels: 17
• Hardware Qtouch Acquisition: Yes
• Max I/o Pins: 36
• Ext Interrupts: 36
• Usb Speed: No
• Usb Interface: No
• Spi: 5
• Twi (i2c): 2
• Uart: 4
• Lin: 4
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 12
• Adc Speed (ksps): 460
• Analog Comparators: 8
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 16
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.62 to 3.6
• Operating Voltage (vcc): 1.62 to 3.6
• Fpu: No
• Mpu / Mmu: Yes / No
• Timers: 6
• Output Compare Channels: 18
• Input Capture Channels: 12
• Pwm Channels: 35
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

32145A–12/2011
Figure 8-3.
Internally, the flash memory stores data in 64-bit doublewords. Therefore, the native data size of
the Page Buffer is also a 64-bit doubleword. All locations shown in
bleword locations. Since the HSB bus only has a 32-bit data width, two 32-bit HSB transfers
must be performed to write a 64-bit doubleword into the Page Buffer. The FLASHCDW has logic
to combine two 32-bit HSB transfers into a 64-bit data before writing this 64-bit data into the
Page Buffer. This logic requires the word with the low address to be written to the HSB bus
before the word with the high address. To exemplify, to write a 64-bit value to doubleword X0
residing in page X, first write a 32-bit word to the byte address pointing to address X0, thereafter
write a word to the byte address pointing to address (X0+4).
The page buffer is word-addressable and should only be written with aligned word transfers,
never with byte or halfword transfers. The page buffer can not be read.
The page buffer is also used for writes to the User page.
Page buffer write operations are performed with 4 wait states. Any accesses attempted to the
FLASHCDW on the HSB bus during these cycles will be automatically stalled.
Writing to the page buffer can only change page buffer bits from one to zero, i.e. writing
0xAAAAAAAA to a page buffer location that has the value 0x00000000 will not change the page
buffer value. The only way to change a bit from zero to one is to erase the entire page buffer with
the Clear Page Buffer command.
All locations are doubleword locations
31
27
23
19
15
11
7
3
Page Buffer
30
26
22
18
14
10
Mapping from Page Buffer to Flash
64-bit data
6
2
29
25
21
17
13
9
5
1
28
24
20
16
12
8
4
0
Y31
Y27
Y23
Y19
Y15
Y11
X31
X27
X23
X19
X15
X11
Z31
Z27
Z23
Z19
Z15
Z11
Y7
Y3
X7
X3
Z7
Z3
AT32UC3L0128/256
Z30
Z26
Z22
Z18
Z14
Z10
Y30
Y26
Y22
Y18
Y14
Y10
X30
X26
X22
X18
X14
X10
Y6
Y2
X6
X2
Z6
Z2
Page Y
Page X
Page Z
Flash
Figure 8-3
Z29
Z25
Z21
Z17
Z13
Y29
Y25
Y21
Y17
Y13
X29
X25
X21
X17
X13
Y9
Y5
Y1
X9
X5
X1
Z9
Z5
Z1
are therefore dou-
Z28
Z24
Z20
Z16
Z12
Y28
Y24
Y20
Y16
Y12
X28
X24
X20
X16
X12
Z8
Z4
Z0
Y8
Y4
Y0
X8
X4
X0
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