sdram_ctrl: Implement full read/write/refresh paths and fix bugs

Made-with: Cursor

Author: higuoxing

rtl/gowin/sdram_ctrl.sby

@@ -5,15 +5,28 @@ prove
 [options]
 prove: mode prove
 cover: mode cover
-prove: depth 20
-cover: depth 120
+prove: depth 50
+cover: depth 80
 
 [engines]
 smtbmc z3
 
 [script]
 read -formal sdram_ctrl.v
-proc -norom
+# Scale down all timing so the full init+read+write sequence fits in <80 cycles:
+# INIT_CYCLES = (2000 * 1) / 1000 = 2
+# T_RP=T_RFC=T_MRD=T_RCD=T_CL=T_WR = 2
+# REFRESH_INTERVAL = (4096 / 1 * 1) / 1000 = 4  (so refresh fires every 4 cycles)
+chparam -set CLOCK_FREQ_MHZ 1 sdram_ctrl
+chparam -set INITIALIZATION_WAIT_PERIOD_NS 2000 sdram_ctrl
+chparam -set REFRESH_PERIOD_NS 4096 sdram_ctrl
+chparam -set REFRESH_TIMES 1 sdram_ctrl
+chparam -set T_RP_PERIOD 2 sdram_ctrl
+chparam -set T_RFC_PERIOD 2 sdram_ctrl
+chparam -set T_MRD_PERIOD 2 sdram_ctrl
+chparam -set T_RCD_PERIOD 2 sdram_ctrl
+chparam -set T_CL_PERIOD 2 sdram_ctrl
+chparam -set T_WR_PERIOD 2 sdram_ctrl
 prep -top sdram_ctrl
 
 [files]