Gowin. Implement power saving primitive

As the board on the GW1N-1 chip becomes a rarity, its replacement is the Tangnano1k board with the GW1NZ-1 chip. This chip has a unique mechanism for turning off power to important things such as OSC, PLL, etc. Here we introduce a primitive that allows energy saving to be controlled dynamically. We also bring the names of some functions to uniformity. Signed-off-by: YRabbit <[email protected]>
YosysHQ · Jul 8, 2024 · 7dd4a8c · 7dd4a8c
1 parent ba29343
commit 7dd4a8c
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Showing 7 changed files with 69 additions and 7 deletions.
diff --git a/himbaechel/uarch/gowin/constids.inc b/himbaechel/uarch/gowin/constids.inc
@@ -987,6 +987,10 @@ X(GSR)
 X(GSR0)
 X(GSRI)
 
+// power saving
+X(BANDGAP)
+X(BGEN)
+
 // inverter
 X(INV)
 

diff --git a/himbaechel/uarch/gowin/gowin.cc b/himbaechel/uarch/gowin/gowin.cc
@@ -259,7 +259,7 @@ void GowinImpl::adjust_dsp_pin_mapping(void)
 void GowinImpl::prePlace() { assign_cell_info(); }
 void GowinImpl::postPlace()
 {
-    gwu.have_SP32();
+    gwu.has_SP32();
     if (ctx->debug) {
         log_info("================== Final Placement ===================\n");
         for (auto &cell : ctx->cells) {

diff --git a/himbaechel/uarch/gowin/gowin.h b/himbaechel/uarch/gowin/gowin.h
@@ -99,6 +99,7 @@ NPNR_PACKED_STRUCT(struct Extra_chip_data_POD {
     static constexpr int32_t NEED_SP_FIX = 2;
     static constexpr int32_t NEED_BSRAM_OUTREG_FIX = 4;
     static constexpr int32_t NEED_BLKSEL_FIX = 8;
+    static constexpr int32_t HAS_BANDGAP = 16;
 });
 
 } // namespace
@@ -131,6 +132,7 @@ enum
     GSR_Z = 276,
     VCC_Z = 277,
     VSS_Z = 278,
+    BANDGAP_Z = 279,
 
     // The two least significant bits encode Z for 9-bit adders and
     // multipliers, if they are equal to 0, then we get Z of their common

diff --git a/himbaechel/uarch/gowin/gowin_arch_gen.py b/himbaechel/uarch/gowin/gowin_arch_gen.py
@@ -19,6 +19,7 @@
 CHIP_NEED_SP_FIX           = 0x2
 CHIP_NEED_BSRAM_OUTREG_FIX = 0x4
 CHIP_NEED_BLKSEL_FIX       = 0x8
+CHIP_HAS_BANDGAP           = 0x10
 
 # Z of the bels
 # sync with C++ part!
@@ -46,6 +47,7 @@
 GSR_Z   = 276
 VCC_Z   = 277
 GND_Z   = 278
+BANDGAP_Z = 279
 
 DSP_Z          = 509
 
@@ -338,6 +340,11 @@ def create_extra_funcs(tt: TileType, db: chipdb, x: int, y: int):
             tt.create_wire(wire, "GSRI")
             bel = tt.create_bel("GSR", "GSR", z = GSR_Z)
             tt.add_bel_pin(bel, "GSRI", wire, PinType.INPUT)
+        elif func == 'bandgap':
+            wire = desc['wire']
+            tt.create_wire(wire, "BGEN")
+            bel = tt.create_bel("BANDGAP", "BANDGAP", z = BANDGAP_Z)
+            tt.add_bel_pin(bel, "BGEN", wire, PinType.INPUT)
         if func == 'io16':
             role = desc['role']
             if role == 'MAIN':
@@ -1024,6 +1031,8 @@ def main():
             chip_flags |= CHIP_NEED_BSRAM_OUTREG_FIX;
         if "NEED_BLKSEL_FIX" in db.chip_flags:
             chip_flags |= CHIP_NEED_BLKSEL_FIX;
+        if "HAS_BANDGAP" in db.chip_flags:
+            chip_flags |= CHIP_HAS_BANDGAP;
 
     X = db.cols;
     Y = db.rows;

diff --git a/himbaechel/uarch/gowin/gowin_utils.cc b/himbaechel/uarch/gowin/gowin_utils.cc
@@ -94,7 +94,7 @@ bool GowinUtils::is_diff_io_supported(IdString type)
     return false;
 }
 
-bool GowinUtils::have_bottom_io_cnds(void)
+bool GowinUtils::has_bottom_io_cnds(void)
 {
     const Extra_chip_data_POD *extra = reinterpret_cast<const Extra_chip_data_POD *>(ctx->chip_info->extra_data.get());
     return extra->bottom_io.conditions.size() != 0;
@@ -112,7 +112,13 @@ IdString GowinUtils::get_bottom_io_wire_b_net(int8_t condition)
     return IdString(extra->bottom_io.conditions[condition].wire_b_net);
 }
 
-bool GowinUtils::have_SP32(void)
+bool GowinUtils::has_BANDGAP(void)
+{
+    const Extra_chip_data_POD *extra = reinterpret_cast<const Extra_chip_data_POD *>(ctx->chip_info->extra_data.get());
+    return extra->chip_flags & Extra_chip_data_POD::HAS_BANDGAP;
+}
+
+bool GowinUtils::has_SP32(void)
 {
     const Extra_chip_data_POD *extra = reinterpret_cast<const Extra_chip_data_POD *>(ctx->chip_info->extra_data.get());
     return extra->chip_flags & Extra_chip_data_POD::HAS_SP32;

diff --git a/himbaechel/uarch/gowin/gowin_utils.h b/himbaechel/uarch/gowin/gowin_utils.h
@@ -35,11 +35,14 @@ struct GowinUtils
     BelId get_io_bel_from_iologic(BelId bel);
 
     // BSRAM
-    bool have_SP32(void);
+    bool has_SP32(void);
     bool need_SP_fix(void);
     bool need_BSRAM_OUTREG_fix(void);
     bool need_BLKSEL_fix(void);
 
+    // Power saving
+    bool has_BANDGAP(void);
+
     // DSP
     inline int get_dsp_18_z(int z) const { return z & (~3); }
     inline int get_dsp_9_idx(int z) const { return z & 3; }
@@ -65,7 +68,7 @@ struct GowinUtils
     CellInfo *dsp_bus_dst(const CellInfo *ci, const char *bus_prefix, int wire_num) const;
 
     bool is_diff_io_supported(IdString type);
-    bool have_bottom_io_cnds(void);
+    bool has_bottom_io_cnds(void);
     IdString get_bottom_io_wire_a_net(int8_t condition);
     IdString get_bottom_io_wire_b_net(int8_t condition);
 

diff --git a/himbaechel/uarch/gowin/pack.cc b/himbaechel/uarch/gowin/pack.cc
@@ -68,7 +68,7 @@ struct GowinPacker
 
     void config_bottom_row(CellInfo &ci, Loc loc, uint8_t cnd = Bottom_io_POD::NORMAL)
     {
-        if (!gwu.have_bottom_io_cnds()) {
+        if (!gwu.has_bottom_io_cnds()) {
             return;
         }
         if (!ci.type.in(id_OBUF, id_TBUF, id_IOBUF)) {
@@ -1802,7 +1802,7 @@ struct GowinPacker
         // For GW1N-9/GW1NR-9/GW1NS-4 series, 32/36-bit SP/SPX9 is divided into two
         // SP/SPX9s, which occupy two BSRAMs.
         // So divide it here
-        if ((bit_width == 32 || bit_width == 36) && !gwu.have_SP32()) {
+        if ((bit_width == 32 || bit_width == 36) && !gwu.has_SP32()) {
             divide_sp(ci, new_cells);
             bit_width = ci->params.at(id_BIT_WIDTH).as_int64();
         }
@@ -2839,6 +2839,41 @@ struct GowinPacker
         }
     }
 
+    // ===================================
+    // Global power regulator
+    // ===================================
+    void pack_bandgap(void)
+    {
+        if (!gwu.has_BANDGAP()) {
+            return;
+        }
+        log_info("Pack BANDGAP...\n");
+
+        bool user_bandgap = false;
+        for (auto &cell : ctx->cells) {
+            auto &ci = *cell.second;
+
+            if (ci.type == id_BANDGAP) {
+                user_bandgap = true;
+                break;
+            }
+        }
+        if (!user_bandgap) {
+            // make default BANDGAP
+            auto bandgap_cell = std::make_unique<CellInfo>(ctx, id_BANDGAP, id_BANDGAP);
+            bandgap_cell->addInput(id_BGEN);
+            bandgap_cell->connectPort(id_BGEN, ctx->nets.at(ctx->id("$PACKER_VCC")).get());
+            ctx->cells[bandgap_cell->name] = std::move(bandgap_cell);
+        }
+        if (ctx->verbose) {
+            if (user_bandgap) {
+                log_info("Have user BANDGAP\n");
+            } else {
+                log_info("No user BANDGAP. Make one.\n");
+            }
+        }
+    }
+
     // ===================================
     // Replace INV with LUT
     // ===================================
@@ -2957,6 +2992,9 @@ struct GowinPacker
         pack_gsr();
         ctx->check();
 
+        pack_bandgap();
+        ctx->check();
+
         pack_wideluts();
         ctx->check();