Linx Technologies TRM-915-DTS - Manual (Page 11)

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Writing to Registers
Writing to a volatile register is nearly instantaneous. Writing to a non-volatile
register typically takes 16ms. Because the packet size can vary based on
the need for encoding, there are two possible packet structures. The first
structure writes a value that is less than 128 (ox80) and the second writes
a value that is higher. The higher value must be split into two values. The
following tables show the byte sequences for writing a register in each
case. Figure 14 shows the command to write to a register.
Reading from Registers
A register read command is constructed by placing an escape character
(0xFE) before the register number. The module responds to this command
by sending an ACK (0x06) followed by the register number and register
value. The register value is sent unmodified. For example, if the register
value is 0x83, 0x83 is returned. If the register number is invalid, the module
responds with a NACK (0x15). The command and response are shown in
Figure 15.
Read From Configuration Register
Command
Header Size Escape Address
0xFF 0x02 0xFE REG
Response
ACK Address Value
0x06 REG V1
Figure 15: Read from Configuration Register Command and Response
Configuration Registers
Power Mode - Address = 0x4D; NV Address = 0x02
The Power Mode register (regPWRMODE, addr 0x4D) configures the
operation mode (DTS or LP) and the transmitter output power setting. The
non-volatile register (regNVPWRMODE, addr 0x02) determines the default
setting on power up.
It is important to note that a module configured to operate in LP mode
does not work with a module transmitting in DTS mode, or vice versa.
However, a module configured to operate in any of the three DTS modes
does work with any other module transmitting in any of the DTS modes.
LP mode operation must be low power. Additional power settings are
included for cases where the module is used with a lossy antenna, such as
a PCB loop trace. Figure 16 shows examples of the commands.
Figure 16: Power Mode Command and Response
Power Mode Register Values
V1 Mode Power Setting Output Power
0x00 LP Mode Low -4dBm
0x01 DTS Mode Mid-low +1dBm
0x02 DTS Mode Mid-high +6dBm
0x03 DTS Mode High +11dBm
0x04 DTS Mode Low -4dBm
0x05 LP Mode Mid-low +1dBm
0x06 LP Mode Mid-high +6dBm
0x07 LP Mode High +11dBm
Figure 17: Power Mode Register Values
Power Mode
Read Command Read Response
Header Size Escape Address ACK Address Value
0xFF 0x02 0xFE
0x4D
0x02
0x06
0x4D
0x02
V1
Write Command
Header Size Address Value
0xFF 0x02
0x4D
0x02
V1
Warning: Be sure that the module is properly powered and remains
powered for the duration of the register write. Loss of important
configuration information could occur if the unit loses power during a
non-volatile write cycle.
Write to Configuration Register Command
Command for a Value less than 128 (0x80)
Header Size Address Value
0xFF 0x02 REG V1
Command for a Value greater than 128 (0x80)
Header Size Address Value 1 Value 2
0xFF 0x03 REG 0xFE V2
Figure 14: Write to Configuration Register Command