From e2e0c7abf215c9e14f4bfc8002e627a5059b79d3 Mon Sep 17 00:00:00 2001 From: Pepping <pepping> Date: Tue, 20 Jan 2015 13:43:59 +0000 Subject: [PATCH] Added top comments --- .../reorder/src/vhdl/reorder_sequencer.vhd | 70 +++++++++++++++++++ 1 file changed, 70 insertions(+) diff --git a/libraries/base/reorder/src/vhdl/reorder_sequencer.vhd b/libraries/base/reorder/src/vhdl/reorder_sequencer.vhd index c6dfcbcf75..cd39debba6 100644 --- a/libraries/base/reorder/src/vhdl/reorder_sequencer.vhd +++ b/libraries/base/reorder/src/vhdl/reorder_sequencer.vhd @@ -17,6 +17,76 @@ -- You should have received a copy of the GNU General Public License -- along with this program. If not, see <http://www.gnu.org/licenses/>. -- +-- Purpose: Providing address and control signals for external memory realizing a +-- reordering of the data. Based on alternating read and writes. +-- +-- +-- Description: The values of generic g_reorder_seq determine the rhythm of the +-- sequencer. The sequencer is based on the use of a dualpage memory. +-- While data is written in page 0, page 1 is read. The state machine +-- alternated between reads and writes: read periods and write periods. +-- The number of accesses in a read and wrte period is determined by the +-- values of the generic. +-- The generics are interpreted as follows: +-- +-- - wr_chunksize is the number of samples that are written during a write access. +-- - wr_nof_chunks is the number of write accesses performed during a write period +-- - rd_chunksize is the number of samples that are read during a read access. +-- - rd_nof_chunks is the number of read accesses performed during a read period +-- - gapsize is the address space to be skipped in between two consecutive write or +-- read periods. Gapsize can be used to create byte-alignment in the memory. +-- - nof_blocks determines the number of write and read periods before the page +-- swap takes place. +-- +-- The example shows the following configuration: +-- +-- wr_chunksize : POSITIVE := 8 +-- wr_nof_chunks : POSITIVE := 1; +-- rd_chunksize : POSITIVE := 4; +-- rd_nof_chunks : POSITIVE := 2; +-- gapsize : NATURAL := 0; +-- nof_blocks : POSITIVE := 5; + +-- WR RD +-- -------- -------- +-- |0 | |0,0 | rd_chunksize +-- wr_chunksize | | -------- +-- | | |2,1 | +-- -------- -------- +-- gapsize | | | | +-- -------- -------- +-- |1 | |0,1 | +-- | | -------- +-- | | |3,0 | +-- -------- -------- +-- | | | | +-- -------- -------- +-- |2 | |1,0 | +-- | | -------- +-- | | |3,1 | +-- -------- -------- +-- | | | | +-- -------- -------- +-- |3 | |1,1 | +-- | | -------- +-- | | |4,0 | +-- -------- -------- +-- | | | | +-- -------- -------- +-- |4 | |2,0 | +-- | | -------- +-- | | |4,1 | +-- -------- -------- +-- | | | | +-- -------- -------- +-- page 0 page 1 +-- +-- The index in the write page indicate the write period(0-4) +-- The first index in the read page indicates the read period(0-4) +-- The second index in the read page indicates the chunknumber(0-1) +-- +-- Remarks: + LIBRARY IEEE, common_lib; USE IEEE.STD_LOGIC_1164.ALL; -- GitLab