SLFS040

– DECEMBER 1993

POST OFFICE BOX 655303

DALLAS, TEXAS 75265

21

port and data-bit definitions

The TLS2205 incorporates three programmable ports that must be programmed via the serial port (SCLK,

SDATA, and SPSZ). ID0 must be the first bit shifted into the register; after 15 shifts, the following occurs:

1.

If ID0 = 0 and ID1 = 0, the TLS2205 is selected (see Table 2) and the rest of the data is processed.

2.

PT0 and PT1 determine which port is selected (see Table 3).

3.

The 16 bits of data are serially loaded into the serial port register.

4.

The selected port is loaded with all 16 bits of data. Port A controls the VCM (see Table 4), port B controls

the spindle motor (see Table 5), and port C controls the device functions (see Table 6).

Table 2. Device Select

DEVICE SELECT

ID1

ID0

DESCRIPTION

Chip selected

0

0

The TLC2205 serial port is selected.

0

1

Chip not selected

1

0

1

1

Table 3. Port Selection

PORT SELECT

PT1

PT0

DESCRIPTION

No port

0

0

Null

A

0

1

VCM port A

B

1

0

Spindle-speed port B

C

1

1

System control port C