AT43USB326-AU Atmel, AT43USB326-AU Datasheet - Page 8

• Manufacturer Part Number: AT43USB326-AU
• Description: IC USB KEYBOARD CTRLR 48LQFP
• Manufacturer: Atmel
• Series: AVR®r

Specifications of AT43USB326-AU

• Applications: Keyboard Controller
• Core Processor: AVR
• Program Memory Type: Mask ROM (16 kB)
• Controller Series: AT43USB
• Ram Size: 512 x 8
• Interface: USB
• Number Of I /o: 32
• Voltage - Supply: 4.4 V ~ 5.25 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 48-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

X-, Y- and Z-
Registers
ALU – Arithmetic
Logic Unit
Program Memory
8
AT43USB326
immediate constant data. These instructions apply to the second half of the registers in the
register file – R16..R31. The general SBC, SUB, CP, AND, and OR and all other operations
between two registers or on a single register apply to the entire register file.
As shown in Table 1, each register is also assigned a data memory address, mapping them
directly into the first 32 locations of the user Data Space. Although not being physically imple-
mented as SRAM locations, this memory organization provides great flexibility in access of the
registers, as the X-, Y-, and Z-registers can be set to index any register in the file.
Registers R26..R31 contain some added functions to their general-purpose usage. These reg-
isters are address pointers for indirect addressing of the Data Space. The three indirect
address registers X, Y, and Z are defined as:
In the different addressing modes these address registers have functions as fixed displace-
ment, automatic increment and decrement (see the descriptions for the different instructions).
The high-performance AVR ALU operates in direct connection with all 32 general-purpose
working registers. Within a single clock cycle, ALU operations between registers in the register
file are executed. The ALU operations are divided into three main categories – arithmetic, log-
ical and bit-functions.
The AT43USB326 contains 16K bytes on-chip masked programmable ROM. Since all instruc-
tions are 16- or 32-bit words, the program memory is organized as 8K x 16. The AT43USB326
Program Counter (PC) is 13 bits wide, thus addressing the 8,192 program memory addresses.
Constant tables can be allocated within the entire program memory address space (see the
LPM - Load Program Memory instruction description).
X-register
Y-register
Z-register
15
7
15
7
15
7
R29 ($1D)
R27 ($1B)
R30 ($1F)
YH
XH
ZH
0
0
0
7
7
7
R26 ($1A)
R28 ($1C)
R31 ($1E)
XL
YL
ZL
3313D–USB–04/06
0
0
0
0
0
0