2.1.12 ASB Advanced Options - SMEV RAM
If you enable user access to the SMEV RAM in the ASB Advanced Options dialog box, you can read the contents of the SMEV RAM. For more information, see the ASB Advanced Options section.
When processing channels, the SMEV stores the digitally filtered (that is, averaged) analog‑to‑digital converter (ADC) result values in this RAM. The address locations for these values are reported in the log file generated by the Analog System Builder. Unlike the analog sample sequence controller (ASSC) RAM, the SMEV stores results on a per‑channel basis.
The SMEV continuously overwrites each channel location every time it processes that channel.
As with the ASSC RAM, each ADC result is stored as a 12‑bit value. Because the SMEV RAM is organized as 9‑bit words, two RAM locations must be read to reconstruct a single 12‑bit value.
The exposed SMEV RAM ports are shown in the following table.
| Port Name | Direction | Description |
|---|---|---|
| USER_EV_ADDR[8:0] | Input | User RAM address. Controls the read address for the A‑port of the 512 × 9 SMEV RAM. If unused, tie these signals to logic 0 or logic 1. |
| USER_EV_RD | Input | User RAM read enable (active high). Enables read access from the A‑port of the 512 × 9 SMEV dual‑port RAM. Read data is provided on EV_RAM_DO_A[8:0]. If unused, tie this signal to logic 0. Ensure that USER_EV_RAM_BUSY is logic 0 when this signal is first asserted; otherwise, the data read will not correspond to the USER_EV_ADDR[EV_ASIZE‑1:0] address. |
| USER_EV_RAM_BUSY | Output | SMEV RAM busy indicator (active high). Indicates that either the INIT/CFG soft IP block or the sample monitor and threshold block (SMTR) soft IP block is accessing the A‑port of the SMEV RAM. This signal may be monitored by external user logic or left unconnected if unused. |
| EV_RAM_WR_BUSY_B | Output | SMEV write‑busy indicator (active high). Indicates that the SMEV block is writing to the B‑port of its dual‑port RAM. |
| SMEV_RAM_DOUT | Output | Data output from the A‑port of the SMEV RAM. |
- SMEV Memory Content Report
The SMEV memory content report in the log file appears in the following format:
******************************************************************************
SMEV Memory Content Report
******************************************************************************
Channel Address Bits Value
volt1 75 [08:00] Averaged ADC Result [08:00]
76 [02:00] Averaged ADC Result [11:09]
Each averaged ADC result is stored across two memory locations:
- One location contains bits [8:0]
- A second location contains bits [11:9]
These two values must be combined to reconstruct the full 12‑bit averaged ADC result.