AT90LS2343-1PI Atmel, AT90LS2343-1PI Datasheet - Page 18
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AT90LS2343-1PI
Manufacturer Part Number
AT90LS2343-1PI
Description
IC MCU 2K FLASH 1MHZ IND 8-DIP
Manufacturer
Atmel
Series
AVR® 90LSr
Specifications of AT90LS2343-1PI
Core Processor
AVR
Core Size
8-Bit
Speed
1MHz
Connectivity
SPI
Peripherals
Brown-out Detect/Reset, POR, WDT
Number Of I /o
5
Program Memory Size
2KB (1K x 16)
Program Memory Type
FLASH
Eeprom Size
128 x 8
Ram Size
128 x 8
Voltage - Supply (vcc/vdd)
2.7 V ~ 6 V
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
8-DIP (0.300", 7.62mm)
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Data Converters
-
Status Register – SREG
18
AT90S/LS2323/2343
and OUT, the I/O addresses $00 - $3F must be used. When addressing I/O registers as
SRAM, $20 must be added to these addresses. All I/O register addresses throughout
this document are shown with the SRAM address in parentheses.
For compatibility with future devices, reserved bits should be written to zero if accessed.
Reserved I/O memory addresses should never be written.
Some of the status flags are cleared by writing a logical “1” to them. Note that the CBI
and SBI instructions will operate on all bits in the I/O register, writing a “1” back into any
flag read as set, thus clearing the flag. The CBI and SBI instructions work with registers
$00 to $1F only.
The I/O and peripherals control registers are explained in the following sections.
The AVR Status Register (SREG) at I/O space location $3F ($5F) is defined as:
• Bit 7 – I: Global Interrupt Enable
The global interrupt enable bit must be set (one) for the interrupts to be enabled. The
individual interrupt enable control is then performed in separate control registers. If the
global interrupt enable register is cleared (zero), none of the interrupts are enabled inde-
pendent of the individual interrupt enable settings. The I-bit is cleared by hardware after
an interrupt has occurred and is set by the RETI instruction to enable subsequent
interrupts.
• Bit 6 – T: Bit Copy Storage
The bit copy instructions BLD (Bit LoaD) and BST (Bit STore) use the T-bit as source
and destination for the operated bit. A bit from a register in the register file can be copied
into T by the BST instruction and a bit in T can be copied into a bit in a register in the
register file by the BLD instruction.
• Bit 5 – H: Half-carry Flag
The half-carry flag H indicates a half-carry in some arithmetic operations. See the
Instruction Set description for detailed information.
• Bit 4 – S: Sign Bit, S = N ⊕ V
The S-bit is always an exclusive or between the negative flag N and the two’s comple-
ment overflow flag V. See the Instruction Set description for detailed information.
• Bit 3 – V: Two’s Complement Overflow Flag
The two’s complement overflow flag V supports two’s complement arithmetics. See the
Instruction Set description for detailed information.
• Bit 2 – N: Negative Flag
The negative flag N indicates a negative result from an arithmetical or logical operation.
See the Instruction Set description for detailed information.
• Bit 1 – Z: Zero Flag
The zero flag Z indicates a zero result from an arithmetical or logical operation. See the
Instruction Set description for detailed information.
Bit
$3F ($5F)
Read/Write
Initial Value
R/W
7
0
I
R/W
6
T
0
R/W
H
5
0
R/W
S
4
0
R/W
V
3
0
R/W
N
2
0
R/W
1
Z
0
R/W
C
0
0
1004D–09/01
SREG