Commands in Level 4

Commands in Level 4 are used for operation of servo system, including: seeking error test, Zap servo pulse, to view seeking error signal, to set servo offset and send pulse to actuator etc.

Command C is used for cylinder test with the format of Cxxyy,z,a,b. The execution needs valid Cert. The test will check whether there are missing sector flag, incorrect gray code, position error etc.

—x is threshold of servo (usually is 0);

—if y is not 0, it should be set as test threshold;

—if z is not 0, it should be set as positioning delay;

—if a is valid, the 8^th to 15^th bits stands for circulating time per cylinder, the 7^th bit stands for Post Zap scan, the 6^th bit stands for position scan and the 0^th to 5^th bits are flag of Zap.

Command D is for seeking time test with the format of Dx,y,z,a,b,c .

—if x is not 0, it stands for seeking length; otherwise, random seeking will be tested.

—if y is input, write test will be run; otherwise it should be read test.

—if z is input, it means seeking times; otherwise default times will be used.

—if a is input, test will be run for random head.

—if b is input, test will be only run for head #0.

—if c is input, the result will be output in graph.

Command I is to test head stability with the format of Ix,y,z, where x stands for DAC bit with default value 40h; y stands for testing cylinder (default cylinder is the first of data area) and z is increment of Gain parameter with default value 666h.

Command N is to test specific servo zone for every head with the format of Nx ,where x stands for testing zone. The command is executed only when Cert is valid and is not valid for Barracuda 7200.9 and later drive families.

Command T is used for servo test for specific cylinder with the format of Tx,y,z, where x is specified zone; y is head# and z is logical cylinder. The command can only be executed when Cert is valid.

Command c is to test cylinder 0 with the format of cx, which is only executed when Cert is valid. The command is to test cylinder 0 for each head.

—if x is 0, test program will check driver type and automatically choose MDW or HDW as driver.

—if x is 1, test program will display heads offset of MDW.

—if x is 2, driver type will be set as MDW.

—if x is 3, driver type will be set as HDW.