diff --git a/ARCH/timing_annotation/k4_frac_N8_tileable_register_scan_chain_nonLR_caravel_io_skywater130nm_timing_tt_025C_1v80.yml b/ARCH/timing_annotation/k4_frac_N8_tileable_register_scan_chain_nonLR_caravel_io_skywater130nm_timing_tt_025C_1v80.yml
index 82c1658..fc8e81d 100644
--- a/ARCH/timing_annotation/k4_frac_N8_tileable_register_scan_chain_nonLR_caravel_io_skywater130nm_timing_tt_025C_1v80.yml
+++ b/ARCH/timing_annotation/k4_frac_N8_tileable_register_scan_chain_nonLR_caravel_io_skywater130nm_timing_tt_025C_1v80.yml
@@ -22,5 +22,5 @@ LUT3_DELAY: 2.31e-9
LUT3_OUT_TO_FLE_OUT_DELAY: 2.03e-9
LUT4_DELAY: 2.6e-9
LUT4_OUT_TO_FLE_OUT_DELAY: 2.03e-9
-REGIN_TO_FF0_DELAY: 1.12e-9
+REGIN_TO_FF0_DELAY: 0.58e-9
FF0_TO_FF1_DELAY: 0.56e-9
diff --git a/DOC/source/datasheet/sofa_hd/figures/sofa_hd_fle_arch_timing.svg b/DOC/source/datasheet/sofa_hd/figures/sofa_hd_fle_arch_timing.svg
new file mode 100644
index 0000000..78d1013
--- /dev/null
+++ b/DOC/source/datasheet/sofa_hd/figures/sofa_hd_fle_arch_timing.svg
@@ -0,0 +1,328 @@
+
+
+
diff --git a/DOC/source/datasheet/sofa_hd/figures/sofa_hd_routing_arch.svg b/DOC/source/datasheet/sofa_hd/figures/sofa_hd_routing_arch.svg
new file mode 100644
index 0000000..c8464f2
--- /dev/null
+++ b/DOC/source/datasheet/sofa_hd/figures/sofa_hd_routing_arch.svg
@@ -0,0 +1,365 @@
+
+
+
diff --git a/DOC/source/datasheet/sofa_hd/index.rst b/DOC/source/datasheet/sofa_hd/index.rst
index 8bff100..3b82f44 100644
--- a/DOC/source/datasheet/sofa_hd/index.rst
+++ b/DOC/source/datasheet/sofa_hd/index.rst
@@ -14,3 +14,5 @@ SOFA HD
sofa_hd_clb_arch
sofa_hd_circuit_design
+
+ sofa_hd_timing
diff --git a/DOC/source/datasheet/sofa_hd/sofa_hd_fpga_arch.rst b/DOC/source/datasheet/sofa_hd/sofa_hd_fpga_arch.rst
index 5f503c9..26340a9 100644
--- a/DOC/source/datasheet/sofa_hd/sofa_hd_fpga_arch.rst
+++ b/DOC/source/datasheet/sofa_hd/sofa_hd_fpga_arch.rst
@@ -59,6 +59,50 @@ The FPGA architecture follows a tile-based organization, to exploit the fine-gra
| | | cells. |
+------+----------+----------------------------------------------+
+.. _sofa_hd_fpga_arch_routing_arch:
+
+Routing Architecture
+^^^^^^^^^^^^^^^^^^^^
+
+The routing architecture is based on uni-directional routing tracks, which are interconnected by routing multiplexers.
+:numref:`fig_sofa_hd_routing_arch` illustrates the detailed organization of the routing architecture.
+
+.. _fig_sofa_hd_routing_arch:
+
+.. figure:: ./figures/sofa_hd_routing_arch.svg
+ :width: 80%
+ :alt: Detailed routing architecture
+
+ Detailed routing architecture
+
+The routing architecture consists the following type of routing tracks:
+
+- Length-1 wires (``L1 wires``), which hop over 1 logic block (including I/O block)
+- Length-2 wires (``L2 wires``), which hop over 2 logic block (including I/O block)
+- Length-4 wires (``L4 wires``), which hop over 4 logic block (including I/O block)
+
+Each tile includes two routing channels, i.e., the X-direction routing channel and the Y-direction routing channel, providing horizental and vertical connections to adjacent tiles.
+Each routing channel consists of 40 routing tracks. See details in :numref:`table_sofa_hd_fpga_arch_routing_track_distribution`.
+
+.. _table_sofa_hd_fpga_arch_routing_track_distribution:
+
+.. table:: Routing track distribution of SOFA HD FPGA
+
+ +------------+------------------------------+
+ | Track type | Number of tracks per channel |
+ +============+==============================+
+ | Length-1 | 6 (10%) |
+ +------------+------------------------------+
+ | Length-2 | 6 (10%) |
+ +------------+------------------------------+
+ | Length-4 | 28 (80%) |
+ +------------+------------------------------+
+ | Total | 40 |
+ +------------+------------------------------+
+
+
+
+
.. _sofa_hd_fpga_arch_scan_chain:
Scan-chain
diff --git a/DOC/source/datasheet/sofa_hd/sofa_hd_timing.rst b/DOC/source/datasheet/sofa_hd/sofa_hd_timing.rst
new file mode 100644
index 0000000..12b2ea0
--- /dev/null
+++ b/DOC/source/datasheet/sofa_hd/sofa_hd_timing.rst
@@ -0,0 +1,108 @@
+.. _sofa_hd_timing:
+
+Timing Annotation
+-----------------
+
+.. _sofa_hd_timing_clb:
+
+Configurable Logic Block
+^^^^^^^^^^^^^^^^^^^^^^^^
+
+The path delays in :numref:`fig_sofa_hd_fle_arch_timing` are listed in :numref:`table_sofa_hd_fle_arch_timing`.
+
+.. _fig_sofa_hd_fle_arch_timing:
+
+.. figure:: ./figures/sofa_hd_fle_arch_timing.svg
+ :scale: 30%
+ :alt: Schematic of a logic element used in SOFA HD FPGA
+
+ Schematic of a logic element used in SOFA HD FPGA
+
+.. _table_sofa_hd_fle_arch_timing:
+
+.. table:: Path delays of logic element in the SOFA HD FPGA
+
+ +-------------------------+------------------------------+
+ | Path / Delay | TT (unit: ns) |
+ +=========================+==============================+
+ | in0 -> LUT3_out[0] [1]_ | 2.31 |
+ +-------------------------+------------------------------+
+ | in1 -> LUT3_out[0] [1]_ | 2.31 |
+ +-------------------------+------------------------------+
+ | in2 -> LUT3_out[0] [1]_ | 2.31 |
+ +-------------------------+------------------------------+
+ | in0 -> LUT3_out[1] [1]_ | 2.31 |
+ +-------------------------+------------------------------+
+ | in1 -> LUT3_out[1] [1]_ | 2.31 |
+ +-------------------------+------------------------------+
+ | in2 -> LUT3_out[1] [1]_ | 2.31 |
+ +-------------------------+------------------------------+
+ | in0 -> LUT4_out [1]_ | 2.60 |
+ +-------------------------+------------------------------+
+ | in1 -> LUT4_out [1]_ | 2.60 |
+ +-------------------------+------------------------------+
+ | in2 -> LUT4_out [1]_ | 2.60 |
+ +-------------------------+------------------------------+
+ | in3 -> LUT4_out [1]_ | 2.60 |
+ +-------------------------+------------------------------+
+ | LUT3_out[0] -> A | 0.56 |
+ +-------------------------+------------------------------+
+ | LUT4_out[0] -> A | 0.58 |
+ +-------------------------+------------------------------+
+ | A -> out[0] | 0.88 |
+ +-------------------------+------------------------------+
+ | A -> FF[0] | 0.56 |
+ +-------------------------+------------------------------+
+ | FF[0] -> out[0] | 0.88 |
+ +-------------------------+------------------------------+
+ | LUT3_out[1] -> out[1] | 0.89 |
+ +-------------------------+------------------------------+
+ | LUT3_out[1] -> FF[1] | 0.56 |
+ +-------------------------+------------------------------+
+ | FF[1] -> out[1] | 0.89 |
+ +-------------------------+------------------------------+
+ | regin -> FF[0] | 0.58 |
+ +-------------------------+------------------------------+
+ | FF[0] -> FF[1] | 0.56 |
+ +-------------------------+------------------------------+
+
+.. [1] The LUT input-to-output delay should be different as some inputs are close to output. However, we consider a uniform path delay considering the delay from the farest input ``in[0]`` to output. This is because VPR currently does not have LUT rebalancing techniques.
+
+I/O Block
+^^^^^^^^^
+
+The path delays in :numref:`fig_sofa_hd_embedded_io_schematic` are listed in :numref:`table_sofa_hd_io_timing`.
+
+.. _table_sofa_hd_io_timing:
+
+.. table:: Path delays of I/O circuit in the SOFA HD FPGA
+
+ +-------------------------+------------------------------+
+ | Path / Delay | TT (unit: ns) |
+ +=========================+==============================+
+ | SOC_IN -> FPGA_IN | 0.11 |
+ +-------------------------+------------------------------+
+ | FPGA_OUT -> SOC_OUT | 0.11 |
+ +-------------------------+------------------------------+
+
+Routing Architecture
+^^^^^^^^^^^^^^^^^^^^
+
+The path delays in :numref:`fig_sofa_hd_routing_arch` are listed in :numref:`table_sofa_hd_routing_arch_timing`.
+
+.. _table_sofa_hd_routing_arch_timing:
+
+.. table:: Path delays of routing blocks in the SOFA HD FPGA
+
+ +---------------------------+------------------------------+
+ | Path / Delay | TT (unit: ns) |
+ +===========================+==============================+
+ | A -> B | 1.61 |
+ +---------------------------+------------------------------+
+ | A -> C | 1.61 |
+ +---------------------------+------------------------------+
+ | A -> D | 1.61 |
+ +---------------------------+------------------------------+
+ | B -> E | 1.38 |
+ +---------------------------+------------------------------+
+