TSB41LV04A Datasheet, PDF (45/49 Pages) Texas Instruments – IEEE 1394a FOUR-PORT CABLE TRANSCEIVER/ARBITER

TSB41LV04A
IEEE 1394a FOUR-PORT CABLE TRANSCEIVER/ARBITER
PRINCIPLES OF OPERATION
SLLS379 – OCTOBER 1999
interface reset and disable (continued)
The sequence of events for disabling the PHY-LLC interface when it is in the non-differentiated mode of
operation (ISO terminal is high) is as follows:
D Normal operation. Interface is operating normally, with LPS active, SYSCLK active, status and packet data
reception and transmission via the CTL and D lines, and request activity via the LREQ line.
D LPS deasserted. The LLC deasserts the LPS signal and, within 1.0 µs, terminates any request or interface
bus activity, places its CTL and D outputs into a high-impedance state, and drives its LREQ output low.
D Interface reset. After T_{LPS_RESET} time, the PHY determines that LPS is inactive, terminates any interface
bus activity, and drives its CTL and D outputs low. The PHY-LLC interface is now in the reset state.
D Interface disabled. If the LPS signal remain inactive for T_{LPS_DISABLE} time, the PHY terminates SYSCLK
activity by driving the SYSCLK output low. The PHY-LLC interface is now in the disabled state.
After the interface has been reset, or reset and then disabled, the interface is initialized and restored to normal
operation when LPS is reasserted by the LLC. The timing for interface initialization is shown in Figure 26 and
Figure 27.
(low)
ISO
7 Cycles
SYSCLK
CTL0
CTL1
5 ns. min
10 ns. max
(b)
(c)
(d)
D0 – D7
LREQ
LPS
(a)
TCLK_ACTIVATE
Figure 26. Interface Initialization, ISO Low
The sequence of events for initialization of the PHY-LLC interface when the interface is in the differentiated
mode of operation (ISO terminal is low) is as follows:
D LPS reasserted. After the interface has been in the reset or disabled state for at least the minimum
T_RESTORE time, the LLC causes the interface to be initialized and restored to normal operation by
re-activating the LPS signal. (In the above diagram, the interface is shown in the disabled state with
SYSCLK high-impedance inactive. However, the interface initialization sequence described here is also
executed if the interface is merely reset but not yet disabled.)
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