DW1000 User Manual
© Decawave Ltd 2017
Version 2.12
Page 78 of 242
Sub-Register 0x2F:24 – Digital Diagnostics Test Mode Control
how to program this register for use in Transmit Power Spectrum Test Mode and note that bits 31:0 only are
used in this mode, whilst the 9 least significant bits are ignored in functional modes.
7.2.13 Register file: 0x0B
– Reserved
ID
Length
(octets)
Type
Mnemonic
Description
0x0B
-
-
-
Reserved – this register file is reserved
register file 0x0B is reserved for future use. Please take care not to write to this register as
doing so may cause the DW1000 to malfunction.
7.2.14 Register file: 0x0C
– Receive Frame Wait Timeout Period
ID
Length
(octets)
Type
Mnemonic
Description
0x0C
2
RW
RX_FWTO
Receive Frame Wait Timeout period
register file 0x0C is the receive frame wait timeout period. The receive frame wait timeout
function is provided to allow the external microprocessor to enter a low power state awaiting a valid receive
frame and be woken up by the DW1000 when either a frame is received or the programmed timeout has
elapsed. While many microcontrollers have timers that might be used for this purpose, including this RX
timeout functionality in the DW1000 allows additional flexibility to the system designer in selecting the
microprocessor to optimise the solution. The frame wait timeout is enabled by the RXWTOE bit in
file: 0x04 – System Configuration
When the receiver is enabled (and begins hunting for the preamble sequence) and RXWTOE is set, then the
frame wait timeout counter starts counting the timeout period programmed. Thereafter, assuming no
action is taken to change the operation, one of two things should happen:
a)
The Receive Frame Wait Timeout period elapses. This disables the receiver and sets the RXRFTO
(Receiver Frame Wait Timeout) bit in the status register, (and resets the counter).
b)
A valid receive frame arrives and sets the RXDFR and RXFCG bits in the status register. This stops the
receive frame wait timer counter so RXRFTO will not be set.
The receiver will not re-enable immediately following a RXRFTO (Receiver Frame Wait Timeout) irrespective
of whether the device is using the Double Receive Buffer, see section 4.3, or the Automatic Receiver Re-
enable, see section 5.3.2.
The timeout period should only be programmed when the device IDLE. Programming the timeout value at
other times is not prevented but may result in unpredictable behaviour.
The MRXFCG and MRXRFTO mask bits in the SYS_MASK register may be configured (before enabling the
receiver) to generate interrupts to the controlling microprocessor. If RXWTOE is cleared while the
countdown is running the countdown will be disabled, and RXRFTO will not be set.