at90ls4433 ATMEL Corporation, at90ls4433 Datasheet - Page 7

• Manufacturer Part Number: at90ls4433
• Description: At90s4433 8-bit Avr Microcontroller With 4k Bytes Of In-system Programmable Flash
• Manufacturer: ATMEL Corporation

Architectural
Overview
1042H–AVR–04/03
The fast-access Register File concept contains 32 x 8-bit general purpose working reg-
isters with a single clock cycle access time. This means that during one single clock
cycle, one Arithmetic Logic Unit (ALU) operation is executed. Two operands are output
from the Register File, the operation is executed, and the result is stored back in the
Register File – in one clock cycle.
Six of the 32 registers can be used as three 16-bit indirect address register pointers for
Data Space addressing, enabling efficient address calculations. One of the three
address pointers is also used as the address pointer for the constant table look-up func-
tion. These added function registers are the 16-bit X-, Y-, and Z-register.
The ALU supports arithmetic and logic functions between registers or between a con-
stant and a register. Single register operations are also executed in the ALU. Figure 5
shows the AT90S4433 AVR RISC microcontroller architecture.
In addition to the register operation, the conventional Memory Addressing modes can be
used on the Register File as well. This is enabled by the fact that the Register File is
assigned the 32 lowermost Data Space addresses ($00 - $1F), allowing them to be
accessed as though they were ordinary memory locations.
Figure 5. The AT90S4433 AVR RISC Architecture
Control Lines
Instruction
Instruction
Program
2K X 16
Register
Decoder
Memory
Program
Data Bus 8-bit
Counter
and Control
Registrers
EEPROM
I/O Lines
Purpose
General
128 x 8
256 x 8
SRAM
Status
32 x 8
Data
ALU
20
AT90S/LS4433
Analog to Digital
Timer/Counter
Timer/Counter
Comparator
with PWM
Watchdog
Converter
Interrupt
Analog
UART
Serial
16-bit
Timer
8-bit
Unit
Unit
SPI
7