ATTINY43U-SUR Atmel, ATTINY43U-SUR Datasheet - Page 104
ATTINY43U-SUR
Manufacturer Part Number
ATTINY43U-SUR
Description
MCU AVR 4KB FLASH 8MHZ 20SOIC
Manufacturer
Atmel
Series
AVR® ATtinyr
Datasheet
1.ATTINY43U-SU.pdf
(182 pages)
Specifications of ATTINY43U-SUR
Core Processor
AVR
Core Size
8-Bit
Speed
8MHz
Connectivity
USI
Peripherals
Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
Number Of I /o
16
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 4x10b
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
*
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
- Current page: 104 of 182
- Download datasheet (4Mb)
14.3.3
14.3.4
104
ATtiny43U
SPI Slave Operation Example
Two-wire Mode
The following code demonstrates how to use the USI module as a SPI Slave:
The code is size optimized using only eight instructions (plus return). The code example
assumes that the DO and USCK pins have been enabled as outputs in DDRA. The value stored
in register r16 prior to the function is called is transferred to the master device, and when the
transfer is completed the data received from the master is stored back into the register r16.
Note that the first two instructions are for initialization, only, and need only be executed once.
These instructions set three-wire mode and positive edge clock. The loop is repeated until the
USI Counter Overflow Flag is set.
The USI two-wire mode is compliant to the Inter IC (TWI) bus protocol, but without slew rate lim-
iting on outputs and without input noise filtering. Pin names used in this mode are SCL and SDA.
Figure 14-4
is only the physical layer that is shown since the system operation is highly dependent of the
communication scheme used. The main differences between the master and slave operation at
this level is the serial clock generation which is always done by the master. Only the slave uses
the clock control unit.
Clock generation must be implemented in software, but the shift operation is done automatically
in both devices. Note that clocking only on negative edges for shifting data is of practical use in
this mode. The slave can insert wait states at start or end of transfer by forcing the SCL clock
low. This means that the master must always check if the SCL line was actually released after it
has generated a positive edge.
Since the clock also increments the counter, a counter overflow can be used to indicate that the
transfer is completed. The clock is generated by the master by toggling the USCK pin via the
PORTA register.
init:
...
SlaveSPITransfer:
SlaveSPITransfer_loop:
ldi
out
out
ldi
out
in
sbrs
rjmp
in
ret
shows two USI units operating in two-wire mode, one as master and one as slave. It
r16,(1<<USIWM0)|(1<<USICS1)
USICR,r16
USIDR,r16
r16,(1<<USIOIF)
USISR,r16
r16, USISR
r16, USIOIF
SlaveSPITransfer_loop
r16,USIDR
8048B–AVR–03/09
Related parts for ATTINY43U-SUR
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
Part Number:
Description:
Manufacturer:
Atmel Corporation
Datasheet:
Part Number:
Description:
Microcontrollers (MCU) 512B FL 32B SRAM TIMER ATTINY4 12MHz
Manufacturer:
Atmel
Part Number:
Description:
IC MCU AVR 512B FLASH SOT-23-6
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
IC MCU AVR 512B FLASH SOT-23-6
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
DEV KIT FOR AVR/AVR32
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
INTERVAL AND WIPE/WASH WIPER CONTROL IC WITH DELAY
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
Low-Voltage Voice-Switched IC for Hands-Free Operation
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
MONOLITHIC INTEGRATED FEATUREPHONE CIRCUIT
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
AM-FM Receiver IC U4255BM-M
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
Monolithic Integrated Feature Phone Circuit
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
Multistandard Video-IF and Quasi Parallel Sound Processing
Manufacturer:
ATMEL Corporation
Datasheet: