From: Staf Verhaegen <staf@stafverhaegen.be>
Date: Thu, 22 Apr 2021 13:38:33 +0000 (+0200)
Subject: Revert "add code-comments regarding potential use of FFSynchroniser"
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=63f28fc916c381075dd7f7c269eabea8312bdef8;p=c4m-jtag.git

Revert "add code-comments regarding potential use of FFSynchroniser"

This reverts commit 269255360f8762066ddef51d7ee86d07bd168f80.

Reason for reverting is that I documented upstream why FFSynchronizer
is not used.
https://gitlab.com/Chips4Makers/c4m-jtag/-/commit/b4aa89548fd7439eda24979ab7d8a516c22a360b
---

diff --git a/c4m/nmigen/jtag/tap.py b/c4m/nmigen/jtag/tap.py
index 77034cb..a72c89a 100755
--- a/c4m/nmigen/jtag/tap.py
+++ b/c4m/nmigen/jtag/tap.py
@@ -510,7 +510,6 @@ class TAP(Elaboratable):
                 with m.State("READACK"):
                     with m.If(dmi.ack_o):
                         # Store read data in sr_data.i hold till next read
-                        # Note: could use FFSynchroniser
                         cd += sr_data.i.eq(dmi.dout)
                         m.next = "IDLE"
 
@@ -663,7 +662,6 @@ class TAP(Elaboratable):
             # clockdomain latch update in `domain` clockdomain and see when
             # it has falling edge.
             # At that edge put isir in sr.oe for one `domain` clockdomain
-            # Note: could use FFSynchroniser instead
             update_core = Signal(name=sr.name+"_update_core")
             update_core_prev = Signal(name=sr.name+"_update_core_prev")
             m.d[domain] += [
@@ -680,7 +678,6 @@ class TAP(Elaboratable):
             with m.If(sr_shift):
                 m.d.posjtag += reg.eq(Cat(reg[1:], self.bus.tdi))
             with m.If(sr_capture):
-                # could also use FFSynchroniser here too
                 m.d.posjtag += reg.eq(sr.i)
 
             # tdo = reg[0], tdo_en = shift
@@ -779,8 +776,8 @@ class TAP(Elaboratable):
                             m.next = "READACK"
                 with m.State("READACK"):
                     with m.If(wb.ack):
-                        # Store read data in sr_data.i and keep it there
-                        # til next read. could use FFSynchroniser (see above)
+                        # Store read data in sr_data.i
+                        # and keep it there til next read
                         m.d[domain] += sr_data.i.eq(wb.dat_r)
                         m.next = "IDLE"
                 with m.State("WRITEREAD"):