DW1000 User Manual
© Decawave Ltd 2017
Version 2.12
Page 77 of 242
Field
Description of fields within Register file: 0x08 – Transmit Frame Control
IFSDELAY
reg:08:04
bits:7–0
Inter-Frame Spacing. This delay in preamble symbol times will be applied between successive
transmitted frames. One use of the IFSDELAY is to allow the receiver time to unload and
process the frame before another frame is sent to it. For this reason IFSDELAY is logically
considered to be a post-amble to the transmitted frame, and it begins counting down after the
last symbol of data is sent. Where the transmitter is enabled to begin a new frame the
DW1000 makes sure that IFSDELAY symbol times have passed. A new value of IFSDELAY for
the next frame should not be set until after the end-of-frame
event has occurred. The IFSDELAY sets a minimum time between frames enforced by the
DW1000, assuming that the host has initiated a new transmission. Note: Because of internal IC
delays the on-air gap between the end of the previous frame and the start of the new one is
actually 6 symbol times larger than specified here, e.g. an IFSDELAY setting of 34 will result in
an on-air gap of 40 preamble symbols.
7.2.11 Register file: 0x09
– Transmit Data Buffer
ID
Length
(octets)
Type
Mnemonic
Description
0x09
1024
WO
TX_BUFFER
Transmit Data Buffer
register file 0x09 is the transmit data buffer. Data from the transmit buffer is transmitted
during the data payload portion of the transmitted frame. Section 3
basics of frame transmission and details the various parts of the TX frame.
The general procedure is to write the data frame for transmission into the TX_BUFFER, set the frame length
and other details in the TX_FCTRL register and initiate transmission using in the TXSTRT control bit in
Register file: 0x0D – System Control Register
Note that read operations from the transmit data buffer are NOT supported. Reading the transmit data
buffer during an active transmit can corrupt the transmitted data. A read of the TX_FCTRL register will also
read the transmit data buffer so the TX_FCTRL register should not be read during an active transmit
operation.
7.2.12 Register file: 0x0A
– Delayed Send or Receive Time
ID
Length
(octets)
Type
Mnemonic
Description
0x0A
5
RW
DX_TIME
Delayed Send or Receive Time (40-bit)
register file 0x0A, the Delayed Send or Receive Time, is used to specify a time in the future to
either turn on the receiver to be ready to receive a frame, or to turn on the transmitter and send a frame.
The low-order 9-bits of this register are ignored. Delayed send is initiated by the TXDLYS control bit in
Register file: 0x0D – System Control Register
. Delayed receive is initiated by the RXDLYE bit.
0x0D – System Control Register