diff --git a/apps/litenes/include/memory.h b/apps/litenes/include/memory.h
index c5755bc4..445f9459 100644
--- a/apps/litenes/include/memory.h
+++ b/apps/litenes/include/memory.h
@@ -47,7 +47,10 @@ static inline uint32_t memory_readw(uint32_t address)
 
 static inline uint32_t instr_fetchw(uint32_t address)
 {
-    return instr_fetch(address) | (instr_fetch(address + 1) << 8);
+  extern byte memory[0x10000]; // mmc
+
+  // for super mairo, all fetch are from mmc
+  return *(uint16_t *)(memory + address);
 }
 
 static inline void memory_writew(uint32_t address, uint32_t word_data)
diff --git a/apps/litenes/src/cpu.c b/apps/litenes/src/cpu.c
index c3676ba3..3f2f5766 100644
--- a/apps/litenes/src/cpu.c
+++ b/apps/litenes/src/cpu.c
@@ -192,12 +192,11 @@ inline void cpu_ram_write(uint32_t address, uint32_t byte_data) {
 }
 
 static inline uint32_t cpu_ram_readw(uint32_t address) {
-  return cpu_ram_read(address) | (cpu_ram_read(address + 1) << 8);
+  return *(uint16_t *)(CPU_RAM + address);
 }
 
 static inline void cpu_ram_writew(uint32_t address, uint32_t word_data) {
-  cpu_ram_write(address, word_data & 0xff);
-  cpu_ram_write(address + 1, word_data >> 8);
+  *(uint16_t *)(CPU_RAM + address) = word_data;
 }