The Frequency Register (bit 5) and RAM size (bits 1 - 0) bits are
ignored.
Direct DAC access - this mode sends waveform data to the DAC
directly from the Input Data Register (base + 0C
16
). When this
mode is set, the RAM bank, Frequency Register, and RAM size bits
are ignored. The frequency is set to DC, and the output remains at
the given voltage until the Input Data Register is written to again.
This mode is used to generate an arbitrary waveform whose
frequency and size (number of points) is limited by a controller’s
speed and its amount of memory. This mode is set together with the
"Input Data Register" clock source (bits 5 -3 of byte 1).
Fast Frequency change - this mode is used to continuously change
the output signal frequency in order to make custom frequency
profiles. The AFG outputs a new frequency each time four
(frequency) bytes are written to the Parameter Register. This mode
uses the 4k RAM size. The Frequency Register and RAM size bits
are ignored.
RAM Size
The RAM size (bits 1 - 0 of byte 2) specifies whether one, two, or four
waveforms will comprise the output waveform. If the RAM size is 8k or
16k, the RAM bank (bits 7 - 6) is ignored.
Starting the
Waveform
When register-based programming, the waveform is output when byte 2 of
the output mode is processed by the AFG. If the "external burst" mode is
set, the waveform is output when an external trigger is received.
Querying the AFG
AFG parameters are queried by sending command opcode 13 followed by a
query opcode. The response to the query is returned to the Query Response
Register (base + 08
16
).
The AFG parameters that can be queried include:
•
function
•
frequency (registers 1 and 2)
•
attenuation
•
offset
•
burst count
•
sweep rate
•
mode
Each time opcode 13 and a query opcode are sent one byte is returned. For
example, to query the frequency, opcode 13 must be sent four times (with a
different query code) to return the four bytes which set the frequency.
Appendix C
HP E1340A Register-Based Programming 251
Summary of Contents for E1340A
Page 12: ...Notes 12 HP E1340A Arbitrary Function Generator Module User s Manual ...
Page 14: ...14 HP E1340A Arbitrary Function Generator Module User s Manual ...
Page 42: ...Chapter 2 Generating Standard Waveforms with the HP E1340A 42 ...
Page 54: ...Chapter 2 Generating Standard Waveforms with the HP E1340A 54 ...
Page 58: ...Chapter 3 Generating Arbitrary Waveforms with the HP E1340A 58 ...
Page 84: ...Chapter 4 HP E1340A Sweeping and Frequency Shift Keying 84 ...
Page 130: ...Chapter 6 HP E1340A High Speed Operation 130 ...
Page 202: ...202 HP E1340A SCPI Conformance Information Chapter 7 ...
Page 218: ...218 HP E1340A Specifications Appendix A ...
Page 284: ...284 HP E1340A Register Based Programming Appendix C ...
Page 295: ...Index HP E1340A Arbitrary Function Generator User s Manual 295 ...