This is radix-16 Viterbi detector core being developed for PRML(Partial Response Maximum Likelihood), which is widely used in HDD/ODD read channel signal processing. Based on our original ACS and pass memory algorithm, both of small-size and low-latency is achieved at the same time.
Introduction
Four kinds of products are selectable to meet different demands.
| Product No | Type | Soft-Output |
|---|---|---|
| Si2540 | Small-size | No |
| Si2540-H | High-speed | No |
| Si2540-S | Small-size | Yes |
| Si2540-HS | High-speed | Yes |
Features
・Simplified ACS loop for high-speed design
・Radix-16
・ 8-State
・PR(Partial Response) transfer function configurable
・Traceback length configurable
・Support soft-output
・Available two type : small-size, high-speed
・Low latency
・Fully synchronous design using a single clock
・ASIC friendly design
Deliverables
- Verilog RTL source code
- FPGA netlist (Xilinx, Altera, Lattice, etc.)
- -ASIC netlist (need ASIC cell library)
- -CPU/DSP source code (C, Assembler) Especially we've got high experience on TI's DSP.
Test bench and test patterns are also provided.
Gate Count / Performance
TSMC 65nmLP
| Product No | Si2540 | Si2540-H |
|---|---|---|
| Gate Count | 206Kgate | 285Kgate |
| Frequency | 500MHz | 555MHz |
| Latency | 56sample | 64sample |
| Data Rate | 2Gbps | 2.2Gbps |
Experience
・Successfully adopted in ASIC
Interface
Input
| Name | Description |
|---|---|
| ICLK | Clock |
| IXRST | Asynchronous reset |
| IDATA0[n-1:0] | Input data (t) |
| IDATA1[n-1:0] | Input data (t-1) |
| IDATA2[n-1:0] | Input data (t-2) |
| IDATA3[n-1:0] | Input data (t-3) |
| IPR_A[m-1:0] | PR transfer function A |
| IPR_B[m-1:0] | PR transfer function B |
| IPR_C[m-1:0] | PR transfer function C |
| IPR_D[m-1:0] | PR transfer function D |
*1: Only for Si2540-S, Si2540-HS
*1：Si2540-S、Si2540-HS のみ
Output
| Name | Description |
|---|---|
| ODATA[3:0] | Detected data |
| OSDATA0[s-1:0] | Soft-output (t) (*1) |
| OSDATA1[s-1:0] | Soft-output (t-1) (*1) |
| OSDATA2[s-1:0] | Soft-output (t-2) (*1) |
| OSDATA3[s-1:0] | Soft-output (t-3) (*1) |
Applications
Hard disk drive(HDD), Optical disc drive(ODD)
Customization
- Change radix (Radix-2, Radix-4, Radix-8 etc.)
- Change number of state (4-State, 16-State etc.)
- Add data dependent noise prediction (below figure)
- Add signal distortion compensation
For more information/customization on Viterbi detector, please contact us.
The content might change without a previous notice due to the improvement.