Keysight E4428C ESG RF Programming Manual page 256

Creating and Downloading Waveform Files
Creating Waveform Data
Line Code Description—Interleaving and Byte Swapping for Little Endian Order
21–29
the I and Q data), and interleave the I and Q data.
—
shift the data pointer right 8 bits to the beginning of the high byte (ivalue >> 8)
—
AND (boolean) the high I byte with 0xFF to make the high I byte the value to store in the IQ
array—(ivalue >> 8) & 0xFF
—
AND (boolean) the low I byte with 0xFF (ivalue & 0xFF) to make the low I byte the value to store
in the I/Q array location just after the high byte [index * 4 + 1]
—
Swap the Q byte order within the same loop. Notice that the I and Q data interleave with each loop
cycle. This is due to the I/Q array shifting by one location for each I and Q operation [index * 4 +
n].
248
Little Endian Order
7 6 5 4 3 2
1 1 1 0 1 0 0 1
Data pointer
15 14 13 12 11 10
1 0 1 1 0 1 1 1
1 1 1 1 1 1 1 1
1 0 1 1 0 1 1 1
I Data in I/Q Array after Byte Swap (Big Endian Order)
15 14 13 12 11 10
1 0 1 1 0 1 1 1
Interleaved I/Q Array in Big Endian Order
15...................... 8 7....................
1 0 1 1 0 1 1 1 1 1 1 0 1 0 0 1
I Data
1 0 15 14 13 12 11 10
1 0 1 1 0 1 1 1
Data pointer shifted 8 bits
9 8
Hex value =B7
Hex value =FF
Hex value =B7
9 8 7 6 5 4 3
1 1 1 0 1 0 0 1
15...................... 8
0
1 1 1 0 0 1 0 1
Q Data
Keysight Signal Generators Programming Guide
Bit Position
9 8
Data
Hex values = E9 B7
Bit Position
2 1 0
Data
Hex value = B7 E9
Bit Position
7.................... 0
0 1 1 0 1 0 1 1
Data