15.15.1 Digital Interface Timing Characteristics

Note: This is for internal communication between the AT86RF212B transceiver and the SAM L21 microcontroller.

Test Conditions: TOP = +25°C, VDD = 3.0V, CLoad = 50pF (unless otherwise stated).

Symbol Parameter Condition Min. Typ. Max. Unit
fsync SCLK frequency Synchronous operation 8 MHz
fasync SCLK frequency Asynchronous operation 7.5 MHz
t1 /SEL falling edge to MISO active 180 ns
t2 SCLK falling edge to MISO out Data hold time 25 ns
t3 MOSI setup time 10 ns
t4 MOSI hold time 10 ns
t5 LSB last byte to MSB next byte 250(1) ns
t6 /SEL rising edge to MISO tri state 10 ns
t7 SLP_TR pulse width TX start trigger 62.5 Note(2) ns
t8 SPI idle time: SEL rising to falling edge

SPI read/write, standard SRAM and frame access modes

Idle time between consecutive SPI accesses

 250 ns
t8a SPI idle time: SEL rising to falling edge

Fast SRAM read/write access mode

Idle time between consecutive SPI accesses

 500 ns
t9 SCLK rising edge LSB to /SEL rising edge 250 ns
t10 Reset pulse width ≥ 10 clock cycles at 16MHz 625 ns
t11 SPI access latency after reset ≥ 10 clock cycles at 16MHz 625 ns
t12 Dynamic frame buffer protection: IRQ latency 750 ns
tIRQ IRQ_2, IRQ_3, IRQ_4 latency Relative to the event to be indicated 9 µs
fCLKM Output clock frequency at pin 17 (CLKM)

Configurable by the CLKM_CTRL bits in the TRX_CTRL 0 register (TRX_CTRL_0.CLKM_CTRL)

CLKM_CTRL = 0

 0 MHz
CLKM_CTRL = 1 1 MHz
CLKM_CTRL = 2 2 MHz
CLKM_CTRL = 3 4 MHz
CLKM_CTRL = 4 8 MHz
CLKM_CTRL = 5 16 MHz
CLKM_CTRL = 6 250 kHz
CLKM_CTRL = 7(3) 20.0 kHz
CLKM_CTRL = 7(4) 40.0 kHz
CLKM_CTRL = 7(5) 25.0 kHz
CLKM_CTRL = 7(6) 62.5 kHz
  1. For Fast SRAM read/write accesses on address space 0x82 – 0x94 the time t5(Min.) and t8(Min.) increases to 500ns.
  2. Maximum pulse width less than (TX frame length + 16µs).
  3. 1/50MHz; Only in BPSK mode with fPSDU = 20kb/s.
  4. 1/25MHz; Only in BPSK mode with fPSDU = 40kb/s.
  5. 1/40MHz; Only in O-QPSK mode with fPSDU = 100/200/400kb/s.
  6. 1/16MHz; Only in O-QPSK mode with fPSDU = 250/500/1000kb/s.