CC2480 output power?

JeffreyBritton

Other Parts Discussed in Thread: CC2430

The SysTestRF message allows changing the txPower level for testing. However, it appears that there is no method to change the txPower during normal operation. Additionally, the default value for txPower is not documented. I would like to know the default value for txPower. Note that SysTestRF does not provide a value for 0dBm.

Does the ZStack on the CC2480 set the TXCTRLL register to control this? The documented values for the CC2430 TXCTRLL register do not seem to correspond with the SysTestRF message for the CC2480.

over 17 years ago

0 JeffreyBritton over 17 years ago

Intellectual 535 points

Upon some digging in the ZStack source code it looks like

#define MAC_RADIO_TX_POWER_DEFAULT 0x1F

TXCTRLL is set to 0x1F by default.

However, I am unable to track down how SYS_TEST_RF changes this value, which makes me wonder if I really found the correct setting.

Furthermore, 0x1F is not a documented value for TXCTRLL for the CC2430. Is the CC2480 different somehow with respect to this?

0x1F is documented in the SYS_TEST_RF as -1.5dBm.

0 "Double 0" over 17 years ago in reply to JeffreyBritton

TI__Expert 4155 points

The power table that is used in the CC2480 is:

const uint8 CODE macRadioDefsTxPowerTable[] =
{
/*   0 dBm */   0x5F,   /* characterized as -0.4 dBm in datasheet */
/* -1 dBm */   0x3F,   /* characterized as -0.9 dBm in datasheet */
/* -2 dBm */   0x3F,
/* -3 dBm */   0x1B,   /* characterized as -2.7 dBm in datasheet */
/* -4 dBm */   0x17,   /* characterized as -4.0 dBm in datasheet */
/* -5 dBm */   0x13,
/* -6 dBm */   0x13,   /* characterized as -5.7 dBm in datasheet */
/* -7 dBm */   0x13,
/* -8 dBm */   0x0F,   /* characterized as -7.9 dBm in datasheet */
/* -9 dBm */   0x0F,
/* -10 dBm */   0x0F,
/* -11 dBm */   0x0B,   /* characterized as -10.8 dBm in datasheet */
/* -12 dBm */   0x0B,
/* -13 dBm */   0x0B,
/* -14 dBm */   0x0B,
/* -15 dBm */   0x07,   /* characterized as -15.4 dBm in datasheet */
/* -16 dBm */   0x07,
/* -17 dBm */   0x07,
/* -18 dBm */   0x07,
/* -19 dBm */   0x06,   /* characterized as -18.6 dBm in datasheet */
/* -20 dBm */   0x06,
/* -21 dBm */   0x06,
/* -22 dBm */   0x06,
/* -23 dBm */   0x06,
/* -24 dBm */   0x06,
/* -25 dBm */   0x03    /* characterized as -25.2 dBm in datasheet */
};

The "magic" command is CMD1 byte = 0x0F (sys stack tune), next byte = attribute value = RF power (0x14), then followed by the value which is an index into the array shown above.

We will document this magic command and possibly other magic commands in the next version of the interface spec...