1–5
Table 1–1. Terminal Functions (Continued)
TERMINAL
I/O
DESCRIPTION
NAME
NO.
Phy Interface
CTL1, CTL0
62, 63
I/O
Control 1 and control 0 of the phy-link control bus. CTL1 and CTL0 indicate the four
operations that can occur in this interface (see Section 7 of this document or Annex
J of the IEEE 1394-1995 standard for more information about the four operations).
D0 – D7
52–55
57–60
I/O
Data 0 through data 7 of the phy-link data bus. Data is expected on D0 – D1 for
100 Mb/s packets, D0 – D3 for 200 Mb/s, and D0 – D7 for 400 Mb/s.
ISO
69
I
Isolation barrier (active low). This ISO is asserted (low) when an isolation barrier is
present.
LREQ
67
O
Link request. LREQ is a TSB12C01A output that makes bus requests and accesses
the phy layer.
POWERON
76
O
Power on indicator to phy interface. When active, POWERON has a clock output with
1/32 of the BCLK frequency and indicates to the phy interface that the TSB12C01A
is powered. This terminal can be connected to the link power status (LPS) terminal
on the TI phy devices to provide an indication of the LLC power condition.
SCLK
65
I
System clock. SCLK is a 49.152-MHz clock from the phy, that generates the
24.576-MHz clock.
Miscellaneous Signals
BCLK
32
I
Bus clock. BCLK is the host bus clock used in the host-interface module of the
TSB12C01A. It is asynchronous to SCLK.
CYCLEIN
42
I
Cycle in. CYCLEIN is an optional external 8,000-Hz clock used as the cycle clock,
and it should only be used when attached to the cycle-master node. It is enabled by
the cycle source bit and should be tied high when not used.
CYCLEOUT
44
O
Cycle out. CYCLEOUT is the TSB12C01A version of the cycle clock. It is based on
the timer controls and received cycle-start messages.
CYDNE
49
O
Status of CyDne bit. When the RevAEn bit of the control register is set, CYDNE
indicates the value of the CyDne bit of the interrupt register. When RevAEn is cleared,
CYDNE is a 3-state output.
CYST
50
O
Status of CySt bit. When the RevAEn bit of the control register is set, CYST indicates
the value of the CySt bit of the interrupt register. When RevAEn is cleared, CYST is
a 3-state output.
GND
1, 11,
21, 31,
38, 40,
41,
45–47,
51, 61,
66, 68,
70,
78–81,
91
Ground reference
GRFEMP
48
O
Status of Empty bit. When the RevAEn bit of the control register is set, GRFEMP
indicates the value of the Empty bit of the GRF status register. When RevAEn is
cleared, GRFEMP is a 3-state output.
RAMEz
77
I
RAM 3-state enable. When RAMEz is deasserted (low), FIFOs are enabled. When
RAMEz is asserted, the FIFOs are 3-state outputs. (This is a manufacturing
test-mode condition and should be grounded under normal operating conditions.)