AT91SAM7X128-CU Atmel, AT91SAM7X128-CU Datasheet - Page 657

• Manufacturer Part Number: AT91SAM7X128-CU
• Description: MCU ARM 128K HS FLASH 100-TFBGA
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM7X128-CU

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 55MHz
• Connectivity: CAN, Ethernet, I²C, SPI, SSC, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, DMA, POR, PWM, WDT
• Number Of I /o: 62
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: FLASH
• Ram Size: 32K 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: 100-TFBGA
• For Use With: AT91SAM-ICE - EMULATOR FOR AT91 ARM7/ARM9AT91SAM7X-EK - KIT EVAL FOR AT91SAM7X256/128
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

41.3.10
41.3.10.1
41.3.10.2
41.3.10.3
41.3.10.4
41.3.10.5
41.3.11
41.3.11.1
6120H–ATARM–17-Feb-09
Two-wire Interface (TWI)
Universal Synchronous Asynchronous Receiver Transmitter (USART)
TWI: Clock Divider
TWI: Disabling Does not Operate Correctly
TWI: NACK Status Bit Lost
TWI: Possible Receive Holding Register Corruption
TWI: Software Reset
USART: CTS in Hardware Handshaking
The value of CLDIV x 2
must be less than or equal to 8191⋅
None.
Any transfer in progress is immediately frozen if the Control Register (TWI_CR) is written with
the bit MSDIS at 1. Furthermore, the status bits TXCOMP and TXRDY in the Status Register
(TWI_SR) are not reset.
The user must wait for the end of transfer before disabling the TWI. In addition, the interrupts
must be disabled before disabling the TWI.
During a master frame, if TWI_SR is read between the Non Acknowledge condition detection
and the TXCOMP bit rising in the TWI_SR, the NACK bit is not set.
The user must wait for the TXCOMP status bit by interrupt and must not read the TWI_SR as
long as transmission is not completed.
TXCOMP and NACK fields are set simultaneously and the NACK field is reset after the read of
the TWI_SR.
When loading the TWI_RHR, the transfer direction is ignored. The last data byte received in the
TWI_RHR is corrupted at the end of the first subsequent transmit data byte. Neither RXRDY nor
OVERRUN status bits are set if this occurs.
The user must be sure that received data is read before transmitting any new data.
when a software reset is performed during a frame and when TWCK is low, it is impossible to ini-
tiate a new transfer in READ or WRITE mode.
None.
When Hardware Handshaking is used and if CTS goes low near the end of the start bit, a char-
acter can be lost.
CTS must not go high during a time slot occurring between 2 Master Clock periods before and
16 Master Clock periods after the rising edge of the start bit.
Problem Fix/Workaround
Problem Fix/Workaround
Problem Fix/Workaround
Problem Fix/Workaround
Problem Fix/Workaround
Problem Fix/Workaround
CKDIV
AT91SAM7X512/256/128 Preliminary
must be less than or equal to 8191, the value of CHDIV x 2
CKDIV
657