From 6fdab5f85524341d8cf3e0d036d4af2e7a0a9a7d Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sun, 4 Oct 2026 12:18:03 +0000
Subject: [PATCH 1/4] Add CUC quick start code snapshot to README

Co-authored-by: Michal-Pogorzelec <80826463+Michal-Pogorzelec@users.noreply.github.com>
---
 README.md | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index da5b65f..f24f7d0 100644
--- a/README.md
+++ b/README.md
@@ -133,7 +133,23 @@ make clean
 
 ## Quick Start
 
-See the examples.
+Minimal CUC setup (from `examples/cuc_example.c`):
+
+```c
+#include "cuc.h"
+
+cuc_format_t fmt = {CUC_EPOCH_CCSDS, 4, 2};
+cuc_time_t time = cuc_time_from_seconds(1234567.25);
+
+uint8_t buf[CUC_OCTETS_MAX];
+size_t written = 0;
+if (cuc_encode(&time, &fmt, buf, sizeof(buf), &written) != CUC_OK)
+{
+    /* handle error */
+}
+```
+
+See `examples/cuc_example.c` for a full encode/decode flow.
 
 ## Memory Usage
 

From 91fe964eddc029ec8faadaa682ecebfe13233abd Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sun, 4 Oct 2026 12:20:25 +0000
Subject: [PATCH 2/4] Add decode path to README quick start snippet

Co-authored-by: Michal-Pogorzelec <80826463+Michal-Pogorzelec@users.noreply.github.com>
---
 README.md | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/README.md b/README.md
index f24f7d0..f801f47 100644
--- a/README.md
+++ b/README.md
@@ -147,6 +147,14 @@ if (cuc_encode(&time, &fmt, buf, sizeof(buf), &written) != CUC_OK)
 {
     /* handle error */
 }
+
+cuc_format_t decoded_fmt;
+cuc_time_t decoded;
+size_t consumed = 0;
+if (cuc_decode(buf, written, &decoded_fmt, &decoded, &consumed) != CUC_OK)
+{
+    /* handle error */
+}
 ```
 
 See `examples/cuc_example.c` for a full encode/decode flow.

From 349e8f63f0b1c73e1db1ba1a6c5f9ea210a59975 Mon Sep 17 00:00:00 2001
From: Michal Pogorzelec <80826463+Michal-Pogorzelec@users.noreply.github.com>
Date: Sun, 4 Oct 2026 14:31:39 +0200
Subject: [PATCH 3/4] Refactor cuc_time_t initialization in README.md

Updated cuc_time_t initialization to use struct initializer.

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
---
 README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/README.md b/README.md
index f801f47..abd1c41 100644
--- a/README.md
+++ b/README.md
@@ -139,7 +139,7 @@ Minimal CUC setup (from `examples/cuc_example.c`):
 #include "cuc.h"
 
 cuc_format_t fmt = {CUC_EPOCH_CCSDS, 4, 2};
-cuc_time_t time = cuc_time_from_seconds(1234567.25);
+cuc_time_t time = {UINT64_C(1234567), UINT64_C(1) << 62};
 
 uint8_t buf[CUC_OCTETS_MAX];
 size_t written = 0;

From 3ff9f3346c41c6e258aadac6976950031369ce9c Mon Sep 17 00:00:00 2001
From: Michal Pogorzelec <michalpogorzelec10@gmail.com>
Date: Sun, 4 Oct 2026 14:37:16 +0200
Subject: [PATCH 4/4] refactor(example): update cuc_example.c for clarity and
 integer-only usage

---
 examples/cuc_example.c | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/examples/cuc_example.c b/examples/cuc_example.c
index 1bf1513..d283c5f 100644
--- a/examples/cuc_example.c
+++ b/examples/cuc_example.c
@@ -5,6 +5,11 @@
  * Encodes a time value into a self-identified CUC code and decodes it back,
  * printing the intermediate octets. Demonstrates CCSDS 301.0-B-4, Section 3.2.
  *
+ * The example stays integer-only, like the codec itself, so it builds and runs
+ * unchanged on targets without an FPU and under -DCUC_NO_FLOAT. The optional
+ * cuc_time_to_seconds() / cuc_time_from_seconds() helpers are deliberately
+ * unused here.
+ *
  * OpenSpaceCode — https://github.com/OpenSpaceCode
  */
 
@@ -16,7 +21,10 @@ int main(void)
 {
     /* 4 octets of seconds, 2 octets of fraction, CCSDS 1958 TAI epoch. */
     cuc_format_t fmt = {CUC_EPOCH_CCSDS, 4, 2};
-    cuc_time_t time = cuc_time_from_seconds(1234567.25);
+
+    /* 1234567.25 s since the epoch. The fraction is an unsigned Q0.64 binary
+     * fraction of a second, so a quarter second is 2^64 / 4, i.e. 1 << 62. */
+    cuc_time_t time = {UINT64_C(1234567), UINT64_C(1) << 62};
 
     uint8_t buf[CUC_OCTETS_MAX];
     size_t written = 0;
@@ -42,8 +50,15 @@ int main(void)
         return 1;
     }
 
-    printf("decoded: %.3f s (%u basic + %u fractional octets)\n",
-           cuc_time_to_seconds(&decoded),
+    /* Render the Q0.64 fraction as milliseconds without floating point. Scaling
+     * only the top 32 bits keeps the product inside uint64_t, and the discarded
+     * low bits are worth less than 2^-32 s. */
+    uint32_t fraction_hi = (uint32_t)(decoded.fraction >> 32);
+    uint32_t milliseconds = (uint32_t)(((uint64_t)fraction_hi * 1000u) >> 32);
+
+    printf("decoded: %llu.%03u s (%u basic + %u fractional octets)\n",
+           (unsigned long long)decoded.seconds,
+           milliseconds,
            decoded_fmt.basic_octets,
            decoded_fmt.fraction_octets);
     return 0;