RTX-24EM
User guide
The technical characteristics can change without notice. AUR°EL S.p.A doesn’t assume the responsibility to the damages caused by an improper use of the device.
AUR°EL S.p.A.
Via Foro dei Tigli, 4 - 47015 Modigliana (FC) – ITALY 12/11/2019 - Rev. B
Tel.: +390546941124 – Fax: +390546941660 Page 25
http://www.aurel.it
9.12 Frequency error register : DFT_Mes[7:0]
This Register located in
RAM2@9[7:0]
is updated by the subroutine in High Sensitivity communication
mode each time that a packet is received.
DFT_Mes[7:0]
contains the signed frequency error between the
transmitter and the receiver RF frequencies.
1LSB corresponds to an offset frequency of 26MHz/32768 = 793Hz.
10
Transmission programming flow
10.1 Transmission flow, mode payload size defined in header
This section describes the entire flow for transmitting RF data, in mode payload size in the header, starting
from the RTX-24EM in power down mode (ENABLE (Pin 10) or nRESET (Pin 4) = GND).
1.
Start the RTX-24EM by setting ENABLE (Pin 10) or nRESET (Pin 4) to Vcc.
2.
Start the crystal oscillator by writing 0b111000000100 (0xE04) in
RAM2
at the address
0
(SPI command
Write_RAM2
).
3.
Wait for crystal oscillator ON: quartz activity can be monitored through
Status[1]
by using a simple
Stop_Micro
SPI command. When
Status[1]
has gone low, the oscillator is ON.
4.
Send the SPI command
ROM_Boot
with
ROM_Boot_Address = 0
to perform the
RAM2
initialization.
5.
Send the SPI command
Write_RAM1
with address =
13
and data write =
1184
(to set RB_Inst_Dis = 1).
6.
Send the SPI command
Start_Micro
.
7.
Wait the IRQ pin to go to high : this will mean that the RAM2 initialization subroutine has been
executed.
8.
Clear IRQ using the SPI command
Clear_IRQ
.
9.
Send the SPI command
ROM_Boot
with
ROM_Boot_Address = 33
to perform the PTAT auto
calibration.
10.
Send the SPI command
Start_Micro
.
11.
Wait the IRQ pin to go to high : this will mean that the PTAT auto calibration subroutine has been
executed.
12.
Clear IRQ using the SPI command
Clear_IRQ
.
13.
Use the SPI command
Write_RAM2
to configure the Address byte
Address[7:0]
(see section 9.7).
14.
Use the SPI command
Write_RAM2
to configure the data rate (
R_Bit_Clk[8:0]
and
Ch_Rate[2:0]
), see
section 9.5).
15.
Use the SPI command
Write_RAM2
to configure the output power (
I_Pre_PA[4:0]
and
I_PA[4:0]
), see
section 9.8).
16.
Use the SPI command
Write_RAM2
to configure the channel frequency (
Frequ[16:0]
), see section 9.6).
17.
Send the SPI command
ROM_Boot
with
ROM_Boot_Address = 64
to perform the VCO auto calibration.
18.
Send the SPI command
Write_RAM1
with address =
53
and data_write =
VcoCalibFreq[11:0]
to
program the center frequency for the auto calibration, see section 9.4.
19.
Send the SPI command
Start_Micro
.
20.
Wait the IRQ pin to go to high : this will mean that the VCO auto calibration subroutine has been
executed.
21.
Clear IRQ using the SPI command
Clear_IRQ
.
