Fujitsu MHK2120AT, MHK2090AT, MHK2060AT, MHJ2181AT manual 1 I/O registers, DA2 DA1 DA0

5.2 Logical Interface

5.2.1 I/O registers

Communication between the host system and the device is done through input- output (I/O) registers of the device.

These I/O registers can be selected by the coded signals, CS0-, CS1-, and DA0 to DA2 from the host system. Table 5.2. shows the coding address and the function of I/O registers.

Table 5.2 I/O registers

CS0–	CS1–	DA2	DA1	DA0	I/O registers		Host I/O
					Read operation	Write operation	address
Command block registers
L	H	L	L	L	Data	Data	X’1F0’
L	H	L	L	H	Error Register	Features	X’1F1’
L	H	L	H	L	Sector Count	Sector Count	X’1F2’
L	H	L	H	H	Sector Number	Sector Number	X’1F3’
L	H	H	L	L	Cylinder Low	Cylinder Low	X’1F4’
L	H	H	L	H	Cylinder High	Cylinder High	X’1F5’
L	H	H	H	L	Device/Head	Device/Head	X’1F6’
L	H	H	H	H	Status	Command	X’1F7’
L	L	X	X	X	(Invalid)	(Invalid)	—
Control block registers
H	L	H	H	L	Alternate Status	Device Control	X’3F6’
H	L	H	H	H	—	—	X’3F7’

Notes:

1.The Data register for read or write operation can be accessed by 16 bit data bus (DATA0 to DATA15).

2.The registers for read or write operation other than the Data registers can be accessed by 8 bit data bus (DATA0 to DATA7).

3.When reading the Drive Address register, bit 7 is high-impedance state.

4.H indicates signal level High and L indicates signal level Low.

And the LBA mode is specified, the Device/Head, Cylinder High, Cylinder Low, and Sector Number registers indicate LBA bits 27 to 24, 23 to 16, 15 to 8, and 7 to 0.

C141-E088-01EN 5-7