ATTINY48-MMHR Atmel, ATTINY48-MMHR Datasheet - Page 184

• Manufacturer Part Number: ATTINY48-MMHR
• Description: MCU AVR 4KB FLASH 12MHZ 28QFN
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY48-MMHR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 12MHz
• Connectivity: I²C, SPI
• Peripherals: Brown-out Detect/Reset, POR, WDT
• Number Of I /o: 24
• Program Memory Size: 4KB (2K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 64 x 8
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

19.0.3
19.1
184
Addressing the Flash During Self-Programming
ATtiny48/88
Performing a Page Write
To execute Page Write, set up the address in the Z-pointer, write “00000101” 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.
The CPU is halted during the Page Write operation.
The Z-pointer is used to address the SPM commands.
Since the Flash is organized in pages (see
Counter can be treated as having two different sections. One section, consisting of the least sig-
nificant bits, is addressing the words within a page, while the most significant bits are addressing
the pages. This is shown in
are addressed independently. Therefore it is of major importance that the software addresses
the same page in both the Page Erase and Page Write operation.
The LPM instruction uses the Z-pointer to store the address. Since this instruction addresses the
Flash byte-by-byte, also the LSB (bit Z0) of the Z-pointer is used.
Figure 19-1. Addressing the Flash During SPM
Note:
Bit
ZH (R31)
ZL (R30)
Z - REGISTER
1. The different variables used in
PROGRAM MEMORY
BIT
PAGE
PROGRAM
COUNTER
15
Z15
15
Z7
7
PAGE ADDRESS
WITHIN THE FLASH
ZPCMSB
PCMSB
Z14
Z6
14
6
Figure
PCPAGE
Z13
13
Z5
19-1. Note that the Page Erase and Page Write operations
5
Figure 19-1
ZPAGEMSB
PAGEMSB
PCWORD
Z12
“Memory Parametrics” on page
Z4
12
4
WORD ADDRESS
WITHIN A PAGE
(1)
are listed in
1
Z11
0
0
11
Z3
3
INSTRUCTION WORD
PAGE
Table 21-1 on page
Z10
10
Z2
2
Z9
Z1
9
1
PCWORD[PAGEMSB:0]:
00
01
02
PAGEEND
191), the Program
191.
Z8
Z0
8
0
8008G–AVR–04/11