TSB41BA3APFP datasheet(49/66 Pages) TI

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TSB41BA3A

IEEE 1394b THREEPORT CABLE TRANSCEIVER/ARBITER

SLLS618B − JUNE 2004 − REVISED AUGUST 2004

POST OFFICE BOX 655303

• DALLAS, TEXAS 75265

PRINCIPLES OF OPERATION (1394a-2000 INTERFACE)

interface reset and disable (continued)

SYSCLK

ISO

(high)

(a)

(c)

(b)

CTL0

D0 − D7

LREQ

LPS

(d)

TCLK_ACTIVATE

CTL1

7 Cycles

Figure 21. Interface Initialization

The sequence of events for initialization of the PHY-LLC is as follows:

(a) LPS reasserted. After the interface has been in the reset or disabled state for at least the minimum

TRESTORE time, the LLC causes the interface to be initialized and restored to normal operation by

reasserting the LPS signal. (In the above diagram, the interface is shown in the disabled state with PCLK

low inactive. However, the interface initialization sequence described here is also executed if the interface

is merely reset but not yet disabled.)

(b) PCLK activated. If the interface is disabled, then the PHY reactivates its PCLK output when it detects that

LPS has been reasserted. If the PHY has entered a low-power state, then it takes between 5.3 to 7.3 ms

for PCLK to be restored; if the PHY is not in a low-power state, then the PCLK is restored within 60 ns. The

PCLK output is a 50% duty cycle square wave with a frequency of 49.152 MHz

±100 ppm (period of

20.345 ns). During the first 7 cycles of PCLK, the PHY continues to drive the CTL and D terminals low. The

LLC is also required to drive its CTL and D outputs low for 1 of the first 6 cycles of PCLK but to otherwise

place its CTL and D outputs in a high-impedance state. The LLC continues to drive its LREQ output low

during this time.

state on the CTL lines and the data-on indication (all 1s) on the D lines for one or more cycles.

(d) Initialization complete. The PHY asserts the idle state on the CTL lines and logic 0 on the D lines. This

indicates that the PHY-LLC interface initialization is complete and normal operation may commence. The

PHY now accepts requests from the LLC via the LREQ line.

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