AT91SAM7X128 Atmel, AT91SAM7X128 Datasheet - Page 665

• Manufacturer Part Number: AT91SAM7X128
• Description: MCU 32-Bit 91S ARM7TDMI RISC 128KB Flash 1.8V/3.3V 100-Pin LQFP
• Manufacturer: Atmel

Specifications of AT91SAM7X128

• Package: 100LQFP
• Device Core: ARM7TDMI
• Family Name: 91S
• Maximum Speed: 55 MHz
• Ram Size: 32 KB
• Program Memory Size: 128 KB
• Operating Supply Voltage: 1.8|3.3 V
• Data Bus Width: 32 Bit
• Program Memory Type: Flash
• Number Of Programmable I/os: 62
• Interface Type: CAN/Ethernet/SPI/I2S/TWI/USART/USB
• On-chip Adc: 8-chx10-bit
• Operating Temperature: -40 to 85 °C
• Number Of Timers: 3

41.4.8.2
41.4.8.3
41.4.9
41.4.9.1
41.4.9.2
6120H–ATARM–17-Feb-09
Two-wire Interface (TWI)
SSC: Transmitter Limitations in Slave Mode
SSC: Transmitter Limitations in Slave Mode
TWI: Clock Divider
TWI: Disabling Does not Operate Correctly
If TK is programmed as output and TF is programmed as input, it is impossible to emit data
when the start of edge (rising or falling) of synchro has a Start Delay equal to zero.
None.
If TK is programmed as an input and TF is programmed as an output and requested to be set to
low/high during data emission, the Frame Synchro signal is generated one bit clock period after
the data start and one data bit is lost. This problem does not exist when generating a periodic
synchro.
The data need to be delayed for one bit clock period with an external assembly. In the following
schematic, TD, TK and NRST are AT91SAM7X signals, TXD is the delayed data to connect to
the device.
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.
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
665