9.5.2 26-Bit 3.23 Number Format

All mixer gain coefficients are 26-bit coefficients using a 3.23 number format. Numbers formatted as 3.23 numbers means that there are 3 bits to the left of the binary point and 23 bits to the right of the binary point. This is shown in Figure 65.

Figure 65. 3.23 Format

The decimal value of a 3.23 format number can be found by following the weighting shown in Figure 65. If the most significant bit is logic 0, the number is a positive number, and the weighting shown yields the correct number. If the most significant bit is a logic 1, then the number is a negative number. In this case every bit must be inverted, a 1 added to the result, and then the weighting shown in Figure 66 applied to obtain the magnitude of the negative number.

Figure 66. Conversion Weighting Factors — 3.23 Format To Floating Point

Gain coefficients, entered via the I²C bus, must be entered as 32-bit binary numbers. The format of the 32-bit number (4-byte or 8-digit hexadecimal number) is shown in Figure 67.

Figure 67. Alignment of 3.23 Coefficient in 32-Bit I²C Word