diff --git a/testbench/openocd_scripts/jtag_cg.tcl b/testbench/openocd_scripts/jtag_cg.tcl
index 1c8dbce3b96..51291eecd4d 100644
--- a/testbench/openocd_scripts/jtag_cg.tcl
+++ b/testbench/openocd_scripts/jtag_cg.tcl
@@ -29,10 +29,12 @@ puts ""
 
 riscv set_mem_access sysbus
 
-set addr1 0x00020008
-set addr2 0x00020508
+set addr1 0xFFFF0000
+set addr2 0x0000FFF0
+set addr3 0x0000FFFF
 set data1 0x05050505
-set data2 0x12345678
+set data2 0xFAFAFAFA
+set data3 0xAB
 
 puts "Write few bytes"
 write_memory $addr1 32 $data1 phys
@@ -61,6 +63,15 @@ if {[compare $actual $data1] != 0} {
     shutdown error
 }
 
+puts "Write 1 byte"
+write_memory $addr3 8 $data3 phys
+
+puts "Read 1 byte"
+set actual [read_memory $addr3 8 1 phys]
+if {[compare $actual $data3] != 0} {
+    shutdown error
+}
+
 # Send signal to call $finish
 write_memory 0xd0580000 8 0xFF phys