A. Load the pre-arm reading count registers. With the digitizer in the idle state, write the decimal equivalent of the least significant byte to register 73. Write the decimal equivalent of the most significant byte to register 75. You can set the pre-arm reading count from 3 to 65,535 readings. For example, to program 500 pre-arm readings, a pre-arm reading count of 498 (500 - 2) is loaded into the registers.

MSB

LSB

0 0 0 0 0 0 0 1

1 1 1 1 0 0 1 0

110

24210

24210 is written to register 73

1 is written to register 75

B. Load the post-arm reading count registers. Write the decimal equivalent of the least significant byte to register 77. Write the decimal equivalent of the middle significant byte to register 79. Write the decimal equivalent of the most significant byte to register 7B. You can set the post-arm reading count from 7 to 16,777,215 readings. For example, to program 100,000 post-arm readings with no pre-arm readings, a post-arm reading count of 99,997 (100,000 -

3)is loaded into the post-arm registers. (A count of 1 is written to the pre-arm registers.)

MSB

MIDSB

LSB

0 0 0 0 0 0 0 1

1 0 0 0 0 1 1 0

1 0 0 1 1 1 0 1

110

13410

15710

15710 is written to register 77

13410 is written to register 79

110 is written to register 7B

3.Initialize the sample rate registers.

A.Write the decimal value of 129 to register base +6316, and write the decimal value of 255 to register base +6116.

B.Disable reference divider reclocking (for divider values greater than 100,000 - see Step 4). Set arm control register

(base +4B16) bit 4 to ’0’ while retaining the settings of the other bits.

Appendix C

Register Programming 383

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Image 383
HP E1429A manual Midsb LSB