ISL5239 Datasheet, PDF (22/31 Pages) Intersil Corporation – Pre-Distortion Linearizer

ISL5239
BIT
15:14
13
12
11:9
8
7
6
5:4
3
2:1
0
TABLE 7. CONTROL
TYPE: CAPTURE MEMORY, ADDRESS: 0x04
FUNCTION
DESCRIPTION
Reserved
Not used.
Address Auto Increment When set high, automatically increments the memory address after any access operation (read or write).
Memory Select
Selects the memory for access.
0 - Input memory (default).
1 - Feedback memory.
Reserved
Not used.
Feedback Input Format
Selects the feedback input format.
0 - Parallel (default) uses FB<19:0> as a 20-bit parallel input.
1 - Serial uses FB<0> as the input data bit and FB<1> as the serial sync, sampled at the rising edge of
FBCLK.
Reserved
Not used.
Processor Trigger
When high, enables the trigger. Low (default) is trigger disabled.
Trigger Select
Selects the trigger mode.
00 - Processor trigger used (default).
01 - Magnitude trigger when min threshold <= magnitude <= maximum threshold.
10 - External trigger.
Reserved
Not used.
Input Memory Data in
Source
Select the input memory dataIn Source.
00 - Interpolator output (default).
01 - Pre-distortion Output.
10 - Pre-distortion Magnitude.
CM Soft Reset
When high, resets all the configuration memory circuitry except the control fields. Low is default.
BIT
15:11
10:0
FUNCTION
Reserved
Input Length
TABLE 8. LENGTH OF INPUT MEMORY LOOP
TYPE: CAPTURE MEMORY, ADDRESS: 0x05
DESCRIPTION
Not Used
Length of the input memory loop. Specified from 2⁰(1) to 2¹¹ (2047). Default = 0. Resets the input
memory address to 0 when input length reached. Actual loop length is this value + 2.
TABLE 9. INPUT MEMORY CAPTURE MODE AND TRIGGER DELAY
TYPE: CAPTURE MEMORY, ADDRESS: 0x06
BIT
FUNCTION
DESCRIPTION
15
Input Memory Capture Selects the active capture mode when the input capture memory is running. Identical to feedback capture
Mode
mode except applies to the input memory.
0 - Delay. (default) Defines the beginning of the 2k sample capture window as the trigger point plus the
input trigger delay counter samples.
1 - Advance. Defines the end of the 2k-sample capture window as the trigger point plus the input trigger
delay counter samples.
See control word 0x07, bit 1:0 for mode selection.
14:0 Input Trigger Delay
Counter
Offset delay that defines the input memory capture window when control word 0x07, bits 1:0 = 01
(Capture mode).
When control word 0x06, bit 15 is set to 0, delay mode, values selectable from 2⁰ to 2¹⁵ (0...32768).
When control word 0x06, bit 15 is set to 1, advance mode, value selectable from 2⁰ to 2¹¹ (0...2047).
22