From d6dbf7bb67b26d79ad81a387c434990b1d194eb7 Mon Sep 17 00:00:00 2001
From: Eric Kooistra <kooistra@astron.nl>
Date: Tue, 20 Feb 2024 14:24:48 +0100
Subject: [PATCH] Add comment on FIFO data width.
---
.../ip_arria10_e1sg/jesd204b/ip_arria10_e1sg_jesd204b_v2.vhd | 4 ++++
.../ip_arria10_e2sg/jesd204b/ip_arria10_e2sg_jesd204b_v2.vhd | 4 ++++
2 files changed, 8 insertions(+)
diff --git a/libraries/technology/ip_arria10_e1sg/jesd204b/ip_arria10_e1sg_jesd204b_v2.vhd b/libraries/technology/ip_arria10_e1sg/jesd204b/ip_arria10_e1sg_jesd204b_v2.vhd
index 1c0d8ec310..8766f1130d 100644
--- a/libraries/technology/ip_arria10_e1sg/jesd204b/ip_arria10_e1sg_jesd204b_v2.vhd
+++ b/libraries/technology/ip_arria10_e1sg/jesd204b/ip_arria10_e1sg_jesd204b_v2.vhd
@@ -497,6 +497,10 @@ begin
-- JESD204B IP is synchronized.
wr_rst <= not wr_core_pll_locked;
+ -- The FIFO g_data_w = c_jesd204b_rx_data_w = 32b does not have to be optimized
+ -- for the fact that the actual ADC data width is 14b instead of 16b. It appears
+ -- that Quartus synthesis will automatically optimize away the unused bits from
+ -- the FIFO data width.
u_dp_fifo_dc_arr : entity dp_lib.dp_fifo_dc_arr
generic map (
g_nof_streams => g_nof_streams,
diff --git a/libraries/technology/ip_arria10_e2sg/jesd204b/ip_arria10_e2sg_jesd204b_v2.vhd b/libraries/technology/ip_arria10_e2sg/jesd204b/ip_arria10_e2sg_jesd204b_v2.vhd
index 79501ebef6..35fbecd22b 100644
--- a/libraries/technology/ip_arria10_e2sg/jesd204b/ip_arria10_e2sg_jesd204b_v2.vhd
+++ b/libraries/technology/ip_arria10_e2sg/jesd204b/ip_arria10_e2sg_jesd204b_v2.vhd
@@ -497,6 +497,10 @@ begin
-- JESD204B IP is synchronized.
wr_rst <= not wr_core_pll_locked;
+ -- The FIFO g_data_w = c_jesd204b_rx_data_w = 32b does not have to be optimized
+ -- for the fact that the actual ADC data width is 14b instead of 16b. It appears
+ -- that Quartus synthesis will automatically optimize away the unused bits from
+ -- the FIFO data width.
u_dp_fifo_dc_arr : entity dp_lib.dp_fifo_dc_arr
generic map (
g_nof_streams => g_nof_streams,
--
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