From ceac8071e049e90fc4e698b3c7cbb4dac6349c57 Mon Sep 17 00:00:00 2001
From: Minseong Jang <minseong.jang@kaist.ac.kr>
Date: Wed, 2 Oct 2024 13:09:11 +0900
Subject: [PATCH] Minor fix

---
 doc/docs/contributors.md                       |  2 +-
 doc/docs/tutorial/fir_filter.md                |  6 +++---
 hazardflow-designs/src/examples/custom_fifo.rs | 17 +++++++++++++----
 3 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/doc/docs/contributors.md b/doc/docs/contributors.md
index da1a1ad..1e82281 100644
--- a/doc/docs/contributors.md
+++ b/doc/docs/contributors.md
@@ -12,7 +12,7 @@ Here is a list of all the people who have worked on HazardFlow:
 - [Gieun Jeong](https://cp.kaist.ac.kr/gieun.jeong/)
 - Jihoon Kim
 
-**Previous Contributos**
+**Previous Contributors**
 
 - Seunghyeon Jeong
 - Tanapoom Sermchaiwong
diff --git a/doc/docs/tutorial/fir_filter.md b/doc/docs/tutorial/fir_filter.md
index 068cf17..54961c1 100644
--- a/doc/docs/tutorial/fir_filter.md
+++ b/doc/docs/tutorial/fir_filter.md
@@ -46,6 +46,7 @@ As in the above figure, it can be divide into 3 submodules: `window`, `weight`,
 
 * It keeps the weight vector `[b0, b1, b2]` persistent throughout the program.
 * It takes the input vector `[v0, v1, v2]` and returns the output vector `[b0·v0, b1·v1, b2·v2]`.
+* This submodule can be simply represented by a `map` combinator.
 
 **`sum` submodule:**
 
@@ -88,9 +89,8 @@ impl<P: Copy + Default> Valid<P> {
 It takes an `Valid<P>` and returns `Valid<Array<P, N>>`.
 It tracks the latest `N` valid input signals.
 The [`fsm_map` interface combinator](https://kaist-cp.github.io/hazardflow/docs/hazardflow_designs/std/hazard/struct.I.html#method.fsm_map) is provided by the HazardFlow HDL standard library.
-It transforms the ingress payload to the egress payload, calculates the next state for the next clock cycle, and leaves the resolver signal untouched.
-It takes an initial state, and an anonymous function, and returns a new interface.
-The initial state is defined as `P::default().repeat::<N>()` in our example.
+It computes the egress payload and the next state based on the ingress payload and the current state, and updates the state when the ingress tranfser happens.
+The initial state is defined as `P::default().repeat::<{ N - 1 }>()` in our example.
 The anonymous function is where we specify the fsm logic from the `(ingress payload, current state)` to the `(egress payload, next state)`.
 
 <!-- 
diff --git a/hazardflow-designs/src/examples/custom_fifo.rs b/hazardflow-designs/src/examples/custom_fifo.rs
index 81cdce9..c718b89 100644
--- a/hazardflow-designs/src/examples/custom_fifo.rs
+++ b/hazardflow-designs/src/examples/custom_fifo.rs
@@ -1,8 +1,11 @@
-//! Masked Merge implementation
+//! Custom FIFO implementation
 
 use crate::prelude::*;
 use crate::std::*;
 
+const N: usize = 5;
+const M: usize = 5;
+
 /// Masked merge trait
 pub trait MaskedMergeExt<P: Copy + Default, const N: usize>: Interface
 where [(); clog2(N)]:
@@ -40,12 +43,18 @@ where [(); clog2(N)]:
 
 /// Masked Merge Combinator
 #[synthesize]
-pub fn custom_fifo(ingress: [Vr<u32>; 5]) -> Vr<u32> {
+pub fn custom_fifo(ingress: [Vr<u32>; N]) -> Vr<u32> {
     ingress
         .masked_merge()
-        .map_resolver::<((), FifoS<(u32, U<{ clog2(5) }>), 5>)>(|er| {
+        .map_resolver::<((), FifoS<(u32, U<{ clog2(N) }>), M>)>(|er| {
             let (_, fifo_s) = er.inner;
-            fifo_s.inner.fold(Array::from([false; 5]), |acc, (_p, idx)| acc.set(idx, true))
+            range::<N>().fold(Array::from([false; N]), |acc, i| {
+                if i.resize() >= fifo_s.len {
+                    acc
+                } else {
+                    acc.set(fifo_s.inner[wrapping_add(fifo_s.raddr, i, M.into_u())].1, true)
+                }
+            })
         })
         .transparent_fifo()
         .map(|(ip, _idx)| ip)