SLAA870 February   2019 AFE7422 , AFE7444

 

  1.   Evaluating the frequency hopping capability of the AFE74xx
    1.     Trademarks
    2. 1 Introduction
    3. 2 Phase Coherency vs Phase Continuity
    4. 3 AFE74xx Architecture
      1. 3.1 AFE74xx Receivers: Multiband DDC
      2. 3.2 AFE74xx Transmitters: Multiband DUC
      3. 3.3 Numerically Controlled Oscillator (NCO)
        1. 3.3.1 Programming the NCO frequency
          1. 3.3.1.1 Example: Programming NCO to 1700MHz
        2. 3.3.2 Direct Digital Synthesis (DDS) Mode
    5. 4 Frequency Hopping Methods
      1. 4.1 Maintaining Phase Continuity
        1. 4.1.1 Phase Continuous Hop Time
          1. 4.1.1.1 Serial Peripheral Interface (SPI)
          2. 4.1.1.2 Test Setup
          3. 4.1.1.3 Software Configuration
          4. 4.1.1.4 Test Results
      2. 4.2 Maintaining Phase Coherency
        1. 4.2.1 TX NCO Hopping Using SPI
          1. 4.2.1.1 TX NCO Switch Using SPI Hop Time
            1. 4.2.1.1.1 Software Configuration
            2. 4.2.1.1.2 Test Results
          2. 4.2.1.2 AFE74xx DAC Settling Time
            1. 4.2.1.2.1 Hardware Setup
            2. 4.2.1.2.2 Software Configuration
            3. 4.2.1.2.3 Test Results
        2. 4.2.2 RX NCO Hopping Using the GPIO Pins
          1. 4.2.2.1 Test Setup
          2. 4.2.2.2 Software Configuration
          3. 4.2.2.3 Test Results
    6. 5 NCO Frequency Resolution Versus Hop Time
    7. 6 Fast Frequency Hopping With the Load and Switch
    8. 7 Register Addresses
    9. 8 References

7 Register Addresses

Table 4 to Table 7 list the register address for all of the available RX and TX NCOs in the AFE74xx. Table 9 lists the register address for the TX NXO selection bit.

Table 4. RXNCO0 Register Address

RXNCO0 Register Address Value Comment
0x16 0xF \\ Open DDC register page of all four ADCs.
0x01E6 \\ RX_NCO0_word[7:0] address
0x01E7 \\ RX_NCO0_word[15:8] address
0x01F0 \\ RX_NCO0_word[23:16] address
0x01F1 \\ RX_NCO0_word[31:24] address

Table 5. RXNCO1 Register Address

RXNCO1 Register Address Value Comment
0x16 0xF \\ Open DDC register page of all four ADCs.
0x01EA \\ RX_NCO0_word[7:0] address
0x01EB \\ RX_NCO0_word[15:8] address
0x01F4 \\ RX_NCO0_word[23:16] address
0x01F5 \\ RX_NCO0_word[31:24] address

Table 6. RXNCO2 Register Address

RXNCO2 Register Address Value Comment
0x16 0xF \\ Open DDC register page of all four ADCs.
0x01EE \\ RX_NCO0_word[7:0] address
0x01EF \\ RX_NCO0_word[15:8] address
0x01F8 \\ RX_NCO0_word[23:16] address
0x01F9 \\ RX_NCO0_word[31:24] address

Table 7. TXNCO0 Register Address

TXNCO0 Register Address Value Comment
0x10 0x55 \\ Open DUC register page of all four DACs.
0x48 \\ TX_NCO0_word[7:0] address
0x49 \\ TX_NCO0_word[15:8] address
0x4A \\ TX_NCO0_word[23:16] address
0x4B \\ TX_NCO0_word[31:24] address

Table 8. TXNCO1 Register Address

TXNCO1 Register Address Value Comment
0x10 0x55 \\ Open DUC register page of all four DACs.
0x0110 \\ TX_NCO1_word[7:0] address
0x0111 \\ TX_NCO1_word[15:8] address
0x0112 \\ TX_NCO1_word[23:16] address
0x0113 \\ TX_NCO1_word[31:24] address

Table 9. TX NCO Selection Address

TX NCO Selection Address Value Comment
0x10 0x55 \\ Open DUC register page of all four DACs.
0x2B 0x23 \\ Select TXNCO0
0x2B 0xA3 \\ Select TXNCO1