Part Number: AFE7444EVM
Hello, TI.
First of all a small feedback.
I've been already struggling with AFE7444 configuration for several week. I've used the main datasheet, programmer's guide and TRM. I found that information is really scattered and information is not given straightforwardly. Also some terms, abbreviations and shortenings, registers names differ in each document!
So, I hope that you could help me to figure out how to set at least the main settings.
My target is:
RX (ADC): Data: 2x16 bit, IQ SR: 491.52 MS/s, ADC SR: 2929.12 MS/s, Decimation: 6
TX (DAC): Data: 2x16 bit, IQ SR: 491.52 MS/s, DAC SR: 8847,36 MS/s, Interpolation 18.
The thing is that those parameters of Decim and Interp are not mentioned in any example table, but in text description, even on the first page, we could find that this device has such configs.
1) Simply I'm really confused with how to set the particular value for Decimation.
It's said that decimation is set in: DDC reg 0x21
But decim field is only 4 bits, how it's possible to use it for example 32 decim factor? Also there is information: "In Half Rate Mode, the decimation factors are halved so that the final output rate is same. In Half Rate Mode, DecimFactorIndex 0 and 1 are invalid"
Half Rate mode is barely mentioned in the main data sheet and also in DDC reg 0x40 description it's said HALF_RATE_MODE "NOT USED"..... Really confusing.
I saved startup sequences for all predefined modes to comapre them! But I haven't found any correlation with the decimation value and the value of register! More over I unintentionally found comment in TRM page 449 reg 0x248: "DecimFactor = 0xD which is Decimation By 3 (IQ)". What is the dependence between reg value and the decimation itself?
2) Absolutely the same situation with Interpolation. It's tx_duc reg 0x26, but I don't understand how to choose it correctly. In the main datasheet on page 68 Table 2 there is some kind of information, but not for all interpolation values!
3) Also there is said that: "The AFE7444 evaluation module (EVM) GUI should be used to set up the AFE7444 in the desired mode and automatically generate all the necessary registers to use for SPI configuration." But there is no any instructions how to use it unless it's not predefined modes!
I tried to set the needed settings in advance tab and then pressed run complete startup sequence also on this tab. But nothing changes. I opened script window and press start recording to follow the sequence but it's always the same! I haven't figure out how to change and save new configuration.
4) Also I haven't found how to estimate/calculate the configuration of JESD according to parameters of DDC/DUC.
I really hope that Ti community could help me with all of these questions. I'm pretty sure that it would help a lot of other new users of AFE74xx.
Looking forward to hearing from you,
Thank you