Altera JESD204B IP - Manual (Page 9)

JESD204B IP Core Configuration
Table 2-1: JESD204B IP Core Configuration
Symbol Description Value
L Number of lanes per converter device 1-8
M Number of converters per device 1-256
F Number of octets per frame 1, 2, 4-256
S Number of transmitted samples per converter per frame 1-32
N Number of conversion bits per converter 1-32
N' Number of transmitted bits per sample (JESD204 word size,
which is in nibble group)
1-32
K Number of frames per multiframe 17/F ≤ K ≤ 32 ; 1-32
CS Number of control bits per conversion sample 0-3
CF Number of control words per frame clock period per link 0-32
HD High Density user data format 0 or 1
LMFC Local multiframe clock (F × K /4) link clock counts (1)
Run-Time Configuration
The JESD204B IP core allows run-time configuration of LMF parameters.
The most critical parameters that must be set correctly during IP generation are the L and F parameters.
Parameter L denotes the maximum lanes supported while parameter F denotes the size of the deskew
buffer needed for deterministic latency. The hardware generates during parameterization, which means
that run-time programmability can only fall back from the parameterized and generated hardware, but
not beyond the parameterized IP core.
You can use run-time configuration for prototyping or evaluating the performance of converter devices
with various LMF configurations. However, in actual production,Altera recommends that you generate
the JESD204B IP core with the intended LMF to get an optimized gate count.
For example, if a converter device supports LMF = 442 and LMF = 222, to check the performance for both
configurations, you need to generate the JESD204B IP core with maximum F and L, which is L = 4 and F
= 2. During operation, you can use the fall back configuration to disable the lanes that are not used in
LMF = 222 mode. You must ensure that other JESD204B configurations like M, N, S, CS, CF, and HD do
not violate the parameter F setting. You can access the Configuration and Status Register (CSR) space to
modify other configurations such as:
• K (multi-frame)
• device and lane IDs
• enable or disable scrambler
• enable or disable character replacement
(1) The value of F x K must be divisible by 4.
2-4 JESD204B IP Core Configuration
UG-01142
2015.05.04
Altera Corporation About the JESD204B IP Core
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