SAM7S16 Atmel Corporation, SAM7S16 Datasheet - Page 618

• Manufacturer Part Number: SAM7S16
• Manufacturer: Atmel Corporation

Specifications of SAM7S16

• Flash (kbytes): 16 Kbytes
• Pin Count: 48
• Max. Operating Frequency: 55 MHz
• Cpu: ARM7TDMI
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 21
• Ext Interrupts: 21
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Uart: 2
• Ssc: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 384
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 4
• Self Program Memory: NO
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8/3.3
• Operating Voltage (vcc): 3.0 to 3.6
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 3
• Input Capture Channels: 3
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: No

40.6.7.5
40.6.8
40.6.8.1
40.6.8.2
40.6.9
40.6.9.1
40.6.9.2
40.6.9.3
618
SAM7S Series
Real Time Timer (RTT)
Serial Peripheral Interface (SPI)
PWM: Behavior of CHIDx Status Bits in the PWM_SR Register
RTT: Possible Event Loss when Reading RTT_SR
RTT: RTT_VR May be Corrupted
SPI: Bad tx_ready Behavior when CSAAT = 1 and SCBR = 1
SPI: LASTXFER (Last Transfer) Behavior
SPI: SPCK Behavior in Master Mode
Erratic behavior of the CHIDx status bit in the PWM_SR Register. When a channel is disabled
by writing in the PWM_DIS Register just after enabling it (before completion of a Clock Period of
the clock selected for the channel), the PWM line is internally disabled but the CHIDx status bit
in the PWM_SR stays at 1.
Do not disable a channel before completion of one period of the selected clock.
If an event (RTTINC or ALMS) occurs within the same slow clock cycle during which the
RTT_SR is read, the corresponding bit might be cleared. This can lead to the loss of this event.
The software must handle the RTT event as an interrupt and should not poll RTT_SR.
Under certain rare circumstances, the Real-time Timer Value (RTT_VR) may be corrupted.
Use RTTINC as an increment for a software counter.
If the SPI is programmed with CSAAT = 1, SCBR(baudrate) = 1 and two transfers are performed
consecutively on the same slave with an IDLE state between them, the tx_ready signal does not
rise after the second data has been transferred in the shifter. This can imply for example, that
the second data is sent twice.
Do not use the combination CSAAT = 1 and SCBR = 1.
In FIXED Mode, with CSAAT bit set, and in “PDC mode” the Chip Select can rise depending on
the data written in the SPI_TDR when the TX_EMPTY flag is set. If for example, the PDC writes
a “1” in the bit 24 (LASTXFER bit) of the SPI_TDR, the chip select will rise as soon as the
TXEMPTY flag is set.
Use the CS in PIO mode when PDC mode is required and CS has to be maintained between
transfers.
SPCK pin can toggle out before the first transfer in Master Mode.
In Master Mode, MSTR bit must be set (in SPI_MR register) before configuring SPI_CSRx
registers.
Problem Fix/Workaround
Problem Fix/Workaround
Problem Fix/Workaround
Problem Fix/Workaround
Problem Fix/Workaround
Problem Fix/Workaround
6175L–ATARM–28-Jul-11