Rainbow Electronics ATmega128RFA1 - Manual (Page 169)

169
8266A-MCU Wireless-12/09
ATmega128RFA1
• Bit 2 – PRRAM2 - Power Reduction SRAM 2
Setting this bit to one will disable the SRAM block 2. Setting this bit to zero will enable
the SRAM block 2.
• Bit 1 – PRRAM1 - Power Reduction SRAM 1
Setting this bit to one will disable the SRAM block 1. Setting this bit to zero will enable
the SRAM block 1.
• Bit 0 – PRRAM0 - Power Reduction SRAM 0
Setting this bit to one will disable the SRAM block 0. Setting this bit to zero will enable
the SRAM block 0.
12.6.5 TRXPR – Transceiver Pin Register
Bit 7 6 5 4 3 2 1 0
NA ($139) Res3 Res2 Res1 Res0 Resx3 Resx2 SLPTR TRXRST TRXPR
Read/Write R R R R RW RW RW RW
Initial Value 0 0 0 0 0 0 0 0
The register TRXPR allows to control basic actions of the radio transceiver like reset or
state transitions. The register bit functionality is inherited from the external pins of the
stand-alone radio transceiver.
• Bit 7:4 – Res3:0 - Reserved
• Bit 3:2 – Resx3:2 - Reserved
• Bit 1 – SLPTR - Multi-purpose Transceiver Control Bit
The bit SLPTR is a multi-functional bit to control transceiver state transitions.
Dependent on the radio transceiver state, a rising edge of bit SLPTR causes the
following state transitions: TRX_OFF => SLEEP (level sensitive), PLL_ON =>
BUSY_TX. Whereas the falling edge of bit SLPTR causes the following state transition:
SLEEP => TRX_OFF (level sensitive). When the radio transceiver is in TRX_OFF state
the microcontroller forces the transceiver to SLEEP by setting SLPTR = H. The
Transceiver awakes when the microcontroller releases the bit SLPTR. In states
PLL_ON and TX_ARET_ON, bit SLPTR is used as trigger input to initiate a TX
transaction. Here SLPTR is sensitive on rising edge only. After initiating a state change
by a rising edge at Bit SLPTR in radio transceiver states TRX_OFF, RX_ON or
RX_AACK_ON, the radio transceiver remains in the new state as long as the pin is
logical high and returns to the preceding state with the falling edge.
• Bit 0 – TRXRST - Force Transceiver Reset
The RESET state is used to set back the state machine and to reset all registers of the
transceiver to their default values. A reset forces the radio transceiver into the
TRX_OFF state and resets all transceiver register to their default values. A reset is
initiated with bit TRXRST = H. The bit is cleared automatically During transceiver reset
the microcontroller has to set the radio transceiver control bit SLPTR to the default
value.