AT32UC3A364-ALUT Atmel, AT32UC3A364-ALUT Datasheet - Page 474

• Manufacturer Part Number: AT32UC3A364-ALUT
• Description: IC MCU 64KB FLASH 144LQFP
• Manufacturer: Atmel
• Series: AVR®32 UC3r

Specifications of AT32UC3A364-ALUT

• Core Processor: AVR
• Core Size: 32-Bit
• Speed: 66MHz
• Connectivity: EBI/EMI, I²C, IrDA, MMC, SPI, SSC, UART/USART, USB OTG
• Peripherals: Brown-out Detect/Reset, DMA, POR, WDT
• Number Of I /o: 110
• Program Memory Size: 64KB (64K x 8)
• Program Memory Type: FLASH
• Ram Size: 128K x 8
• Voltage - Supply (vcc/vdd): 1.65 V ~ 1.95 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 144-LQFP
• Processor Series: AT32UC3x
• Core: AVR32
• Data Bus Width: 32 bit
• Data Ram Size: 96 KB
• Interface Type: IrDA/SCI/SCIF/UDI
• Maximum Clock Frequency: 66 MHz
• Number Of Timers: 3
• Operating Supply Voltage: 3 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR32, EWAVR32-BL, KSK-EVK1100-PL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT, ATEXTWIFI, ATEVK1104
• Minimum Operating Temperature: - 40 C
• Controller Family/series: AT32UC3A
• No. Of I/o's: 110
• Ram Memory Size: 64KB
• Cpu Speed: 66MHz
• No. Of Timers: 2
• Rohs Compliant: Yes
• For Use With: ATEVK1104 - KIT DEV/EVAL FOR AVR32 AT32UC3AATAVRONEKIT - KIT AVR/AVR32 DEBUGGER/PROGRMMRATEVK1100 - KIT DEV/EVAL FOR AVR32 AT32UC3A
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

23.8.2.1
23.8.2.2
32072C–AVR32–2010/03
Clock Generation
Setting up and Performing a Transfer
The Clock Waveform Generator Register (CWGR) is used to control the waveform of the TWCK
clock. CWGR must be programmed so that the desired TWI bus timings are generated. CWGR
describes bus timings as a function of cycles of a prescaled clock. The clock prescaling can be
selected through the EXP field in CWGR.
CWGR has the following fields:
LOW: Prescaled clock cycles in clock low count. Used to time T
HIGH: Prescaled clock cycles in clock high count. Used to time T
STASTO: Prescaled clock cycles in clock high count. Used to time T
DATA: Prescaled clock cycles for data setup and hold count. Used to time T
EXP: Specifies the clock prescaler setting.
Note that the total clock low time generated is the sum of T
Any slave or other bus master taking part in the transfer may extend the TWCK low period at any
time.
The TWIM hardware monitors the state of the TWCK line as required by the I²C specification.
The clock generation counters are started when a high/low level is detected on the TWCK line,
not when the TWIM hardware releases/drives the TWCK line. This means that the CWGR set-
tings alone do not determine the TWCK frequency. The CWGR settings determine the clock low
time and the clock high time, but the TWCK rise and fall times are determined by the external cir-
cuitry (capacitive load, etc.).
Figure 23-5. Bus Timing Diagram
Operation of TWIM is mainly controlled by the Control Register (CR) and the Command Register
(CMDR). The following list presents the main steps in a typical communication:
f
prescaled
S
=
t
t LOW
------------------------- -
2
HD:STA
(
EXP
f
clkpb
+ )
1
t
)
SU:DAT
t HIGH
t
HD:DAT
t LOW
t
t
SU:DAT
SU:STA
HD_DAT
Sr
LOW
HIGH
+ T
AT32UC3A3/A4
. and T
HD_STA
.
SU_DAT
BUF
, T
HD_DAT
+ T
t
SU_STA
.
SU:STO
LOW
, T
.
, T
SU_DAT
SU_STO
P
.
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