TMS279X (WD279X) FLOPPY DISK FORMATTER / CONTROLLER FAMILY

35

* Time doubles when CLK = 1 MHz.

† t SERVICE (WORST CASE): FM 23.5µs, MFM 11.5 µs.

NOTES:

7.

CS# may be permanently tied low if desired.

8.

When writing data into sector tract or data register, user cannot read this register until at least 4 µs in MFM

after the rising edge of WE#. When writing into the command register, status is not valid until some 28 µs in

FM, and 14 µs in MFM Iater. These times are doubled when CLK 1 MHz.

9.

DRQ rising edge: indicates that the data register is empty.

10. DRQ falling edge: indicates that the data register is loaded.

11. INTREQ rising edge: indicates the end of a command.

12. INTREQ falling edge: indicates that the command register is written to.