TI TSB41AB2

 SLLS424F − JUNE 2000 − REVISED MARCH 2004
D Fully Supports Provisions of IEEE
D
D
D
D
D
D
D
D
1394-1995 Standard for High Performance
Serial Bus† and IEEE 1394a-2000
Fully Interoperable With FireWire and
i.LINK Implementation of IEEE Std 1394
Fully Compliant With OpenHCI
Requirements
Provides Two IEEE 1394a-2000 Fully
Compliant Cable Ports at 100/200/400
Megabits Per Second (Mbits/s)
Full IEEE 1394a-2000 Support Includes:
Connection Debounce, Arbitrated Short
Reset, Multispeed Concatenation,
Arbitration Acceleration, Fly-By
Concatenation, Port
Disable/Suspend/Resume
Register Bits Give Software Control of
Contender Bit, Power Class Bits, Link
Active Control Bit and IEEE 1394a-2000
Features
IEEE 1394a-2000 Compliant Common Mode
Noise Filter on Incoming TPBIAS
Extended Resume Signaling for
Compatibility With Legacy DV Devices, and
Terminal- and Register-Compatibility With
TSB41LV02A, Allow Direct Isochronous
Transmit to Legacy DV Devices With Any
Link Layer Even When Root
Power-Down Features to Conserve Energy
in Battery Powered Applications Include:
Automatic Device Power Down During
Suspend, Device Power-Down Terminal,
Link Interface Disable via LPS, and Inactive
Ports Powered Down
D Fail-Safe Circuitry Senses Sudden Loss of
D
D
D
D
D
D
D
D
D
D
D
D
Power to the Device and Disables the Port
to Ensure That the Device Does Not Load
TPBIAS of the Connected Device and
Blocks Any Leakage Path From the Port
Back to the Device Power Plane
Software Device Reset (SWR)
Industry Leading Low Power Consumption
Ultralow-Power Sleep Mode
Cable Power Presence Monitoring
Cable Ports Monitor Line Conditions for
Active Connection to Remote Node
Data Interface to Link Layer Controller
Through 2/4/8 Parallel Lines at 49.152 MHz
Interface to Link Layer Controller Supports
Low-Cost TI Bus-Holder Isolation and
Optional Annex J Electrical Isolation
Interoperable With Link Layer Controllers
Using 3.3 V
Single 3.3-V Supply Operation
Low-Cost 24.576-MHz Crystal Provides
Transmit, Receive Data at 100/200/400
Mbits/s, and Link-Layer Controller Clock at
49.152 MHz
Low-Cost High-Performance 64-Pin TQFP
Thermally Enhanced PowerPAD Package
Increases Thermal Performance by up to
210%
Meets Intel Mobile Power Guideline 2000
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
†Implements technology covered by one or more patents of Apple Computer, Incorporated and SGS Thompson, Limited.
FireWire is a trademark of Apple Computer, Incorporated.
i.LINK is a trademark of Sony Kabushiki Kaisha TA Sony Corporation.
Intel is a trademark of Intel Corporation
Other trademarks are the property of their respective owners.
Copyright  2003 − 2004 Texas Instruments Incorporated
!" # $%&" # '%()$" *"&+
*%$"# $! " #'&$$"# '& ",& "&!# &-# #"%!&"#
#"** ."/+ *%$" '$&##0 *&# " &$&##)/ $)%*&
"&#"0 )) '!&"&#+
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
1
SLLS424F − JUNE 2000 − REVISED MARCH 2004
description
The TSB41AB2 provides the digital and analog transceiver functions needed to implement a two-port node in
a cable-based IEEE 1394 network. The cable ports incorporate two differential line transceivers. The
transceivers include circuitry to monitor the line conditions as needed for determining connection status, for
initialization and arbitration, and for packet reception and transmission. The TSB41AB2 is designed to interface
with a link layer controller (LLC), such as the TSB12LV21, TSB12LV22, TSB12LV23, TSB12LV26, TSB12LV31,
TSB12LV41, TSB12LV42, or TSB12LV01A.
The TSB41AB2 requires only an external 24.576-MHz crystal as a reference. An external clock may be provided
instead of a crystal. An internal oscillator drives an internal phase-locked loop (PLL), which generates the
required 393.216-MHz reference signal. This reference signal is internally divided to provide the clock signals
used to control transmission of the outbound encoded strobe and data information. A 49.152-MHz clock signal
is supplied to the associated LLC for synchronization of the two chips and is used for resynchronization of the
received data. The power-down (PD) function, when enabled by asserting the PD terminal high, stops operation
of the PLL.
The TSB41AB2 supports an optional isolation barrier between itself and its LLC. When the ISO input terminal
is tied high, the LLC interface outputs behave normally. When the ISO terminal is tied low, internal differentiating
logic is enabled, and the outputs are driven such that they can be coupled through a capacitive or transformer
galvanic isolation barrier as described in Annex J of IEEE Std 1394-1995 and in IEEE 1394a-2000 (section
5.9.4) (hereinafter referred to as Annex J type isolation). To operate with TI bus holder isolation, the ISO terminal
on the PHY must be high.
Data bits to be transmitted through the cable ports are received from the LLC on two, four, or eight parallel paths
(depending on the requested transmission speed) and are latched internally in the TSB41AB2 in
synchronization with the 49.152-MHz system clock. These bits are combined serially, encoded, and transmitted
at 98.304, 196.608, or 393.216 Mbits/s (referred to as S100, S200, and S400 speed respectively) as the
outbound data-strobe information stream. During transmission, the encoded data information is transmitted
differentially on the TPB cable pair(s), and the encoded strobe information is transmitted differentially on the
TPA cable pair(s).
During packet reception the TPA and TPB transmitters of the receiving cable port are disabled, and the receivers
for that port are enabled. The encoded data information is received on the TPA cable pair, and the encoded
strobe information is received on the TPB cable pair. The received data-strobe information is decoded to recover
the receive clock signal and the serial data bits. The serial data bits are split into two-, four-, or eight-bit parallel
streams (depending upon the indicated receive speed), resynchronized to the local 49.152-MHz system clock
and sent to the associated LLC.
Both the TPA and TPB cable interfaces incorporate differential comparators to monitor the line states during
initialization and arbitration. The outputs of these comparators are used by the internal logic to determine the
arbitration status. The TPA channel monitors the incoming cable common-mode voltage. The value of this
common-mode voltage is used during arbitration to set the speed of the next packet transmission. In addition,
the TPB channel monitors the incoming cable common-mode voltage on the TPB pair for the presence of the
remotely supplied twisted-pair bias voltage.
The TSB41AB2 provides a 1.86-V nominal bias voltage at the TPBIAS terminal for port termination. This bias
voltage, when seen through a cable by a remote receiver, indicates the presence of an active connection. This
bias voltage source must be stabilized by an external filter capacitor of 1 µF. TPBIAS is close to VDD when an
active port is not connected to another node.
The line drivers in the TSB41AB2 operate in a high-impedance current mode, and are designed to work with
external 112-Ω line-termination resistor networks in order to match the 110-Ω cable impedance. One network
is provided at each end of a twisted-pair cable. Each network is composed of a pair of series-connected 56-Ω
resistors. The midpoint of the pair of resistors that is directly connected to the twisted-pair-A terminals is
connected to its corresponding TPBIAS voltage terminal. The midpoint of the pair of resistors that is directly
2
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SLLS424F − JUNE 2000 − REVISED MARCH 2004
description (continued)
connected to the twisted-pair-B terminals is coupled to ground through a parallel R-C network with
recommended values of 5 kΩ and 220 pF. The values of the external line termination resistors are designed
to meet the standard specifications when connected in parallel with the internal receiver circuits. An external
resistor connected between the R0 and R1 terminals sets the driver output current, along with other internal
operating currents. This current setting resistor has a value of 6.34 kΩ ±1.0%.
When the power supply of the TSB41AB2 is off while the twisted-pair cables are connected, the TSB41AB2
transmitter and receiver circuitry presents a high impedance to the cable and does not load the TPBIAS voltage
at the other end of the cable. Fail-safe circuitry blocks any leakage path from the port back to the device power
plane.
When the TSB41AB2 is used with one of the ports not brought out to a connector, the twisted-pair terminals of
the unused port must be terminated for reliable operation. For each unused port, the TPB+ and TPB− terminals
should be tied together and then pulled to ground, or the TPB+ and TPB− terminals should be connected to the
suggested termination network (see Figure 5). The TPA+ and TPA− and TPBIAS terminals of an unused port
may be left unconnected. The TPBIAS terminal should be connected to a 1-µF capacitor to ground or left
floating.
The TESTM, SE, and SM terminals are used to set up various manufacturing test conditions. For normal
operation, the TESTM terminal should be connected to VDD through a 1-kΩ resistor, SE should be tied to ground
through a 1-kΩ resistor, and SM should be connected directly to ground.
Four package terminals are used as inputs to set the default value for four configuration status bits in the self-ID
packet, and are tied high through a 1-kΩ resistor or hardwired low as a function of the equipment design. The
PC0– PC2 terminals are used to indicate the default power-class status for the node (the need for power from
the cable or the ability to supply power to the cable). See Table 9 for power-class encoding. The C/LKON
terminal is used as an input to indicate that the node is a contender for either isochronous resource manager
(IRM) or bus manager (BM).
The TSB41AB2 supports suspend/resume as defined in IEEE 1394a-2000 specification. The suspend
mechanism allows pairs of directly-connected ports to be placed into a low-power state (suspended state) while
maintaining a port-to-port connection between bus segments. While in the suspended state, a port is unable
to transmit or receive data transaction packets. However, a port in the suspended state is capable of detecting
connection status changes and detecting incoming TPBIAS. When ports of the TSB41AB2 are suspended, all
circuits except the band gap reference generator and bias detection circuits are powered down, resulting in
significant power savings. For additional details of suspend/resume operation see IEEE 1394a-2000. The use
of suspend/resume is recommended for new designs.
The port transmitter and receiver circuitry is disabled during power down (when the PD input terminal is asserted
high), during reset (when the RESET input terminal is asserted low), when no active cable is connected to the
port, or when controlled by the internal arbitration logic. The TPBIAS output is disabled during power down,
during reset, or when the port is disabled as commanded by the LLC.
The cable-not-active (CNA) output terminal is asserted high when there are no twisted-pair cable ports receiving
incoming bias (that is, they are either disconnected or suspended), and can be used along with LPS to determine
when to power down the TSB41AB2. The CNA output is not debounced. When the PD terminal is asserted high,
the CNA detection circuitry is enabled (regardless of the previous state of the ports) and a pulldown is activated
on the RESET terminal to force a reset of the TSB41AB2 internal logic.
The LPS (link power status) terminal works with the C/LKON terminal to manage the power usage in the node.
The LPS signal from the LLC is used in conjunction with the LCtrl bit (see Table 1 and Table 2 in the Application
Information section) to indicate the active/power status of the LLC. The LPS signal is also used to reset, disable,
and initialize the PHY-LLC interface (the state of the PHY-LLC interface is controlled solely by the LPS input
regardless of the state of the LCtrl bit).
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
3
SLLS424F − JUNE 2000 − REVISED MARCH 2004
description (continued)
The LPS input is considered inactive if it remains low for more than 2.6 µs and is considered active otherwise.
When the TSB41AB2 detects that LPS is inactive, it places the PHY-LLC interface into a low-power reset state
in which the CTL and D outputs are held in the logic zero state and the LREQ input is ignored; however, the
SYSCLK output remains active. If the LPS input remains low for more than 26 µs, the PHY-LLC interface is put
into a low-power disabled state in which the SYSCLK output is also held inactive. The PHY-LLC interface is also
held in the disabled state during hardware reset. The TSB41AB2 continues the necessary repeater functions
required for normal network operation regardless of the state of the PHY-LLC interface. When the interface is
in the reset or disabled state and LPS is again observed active, the PHY initializes the interface and returns it
to normal operation.
When the PHY-LLC interface is in the low-power disabled state, the TSB41AB2 automatically enters a
low-power mode if the port is inactive (disconnected, disabled, or suspended). In this low-power mode, the
TSB41AB2 disables its internal clock generators and also disables various voltage and current reference
circuits depending on the state of the port (some reference circuitry must remain active in order to detect new
cable connections, disconnections, or incoming TPBIAS, for example). The lowest power consumption (the
ultralow-power sleep mode) is attained when the port is either disconnected, or disabled with the port interrupt
enable bit cleared. The TSB41AB2 exits the low-power mode when the LPS input is asserted high or when a
port event occurs. This requires that the TSB41AB2 become active in order to respond to the event or to notify
the LLC of the event (for example, incoming bias is detected on a suspended port, a disconnection is detected
on a suspended port, a new connection is detected on a nondisabled port, etc.). The SYSCLK output becomes
active (and the PHY-LLC interface is initialized and become operative) within 7.3 ms after LPS is asserted high
when the TSB41AB2 is in the low-power mode.
The PHY uses the C/LKON terminal to notify the LLC to power up and become active. When activated, the
C/LKON signal is a square wave of approximately 163-ns period. The PHY activates the C/LKON output when
the LLC is inactive and a wake-up event occurs. The LLC is considered inactive when either the LPS input is
inactive, as described above, or the LCtrl bit is cleared to 0. A wake-up event occurs when a link-on PHY packet
addressed to this node is received, or when a PHY interrupt occurs. The PHY deasserts the C/LKON output
when the LLC becomes active (both LPS active and the LCtrl bit set to 1). The PHY also deasserts the C/LKON
output when a bus reset occurs unless a PHY interrupt condition exists which would otherwise cause C/LKON
to be active.
4
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SLLS424F − JUNE 2000 − REVISED MARCH 2004
PAP package terminal diagram
48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33
32
49
50
31
51
30
52
29
53
28
54
27
55
26
56
TSB41AB2
57
25
24
58
23
59
22
60
21
61
20
62
19
63
18
64
1 2
3 4
5
17
6 7 8 9 10 11 12 13 14 15 16
AGND
AVDD
AVDD
SM
SE
TESTM
DVDD
DVDD
CPS
ISO
PC2
PC1
PC0
C/LKON
DGND
DGND
LREQ
SYSCLK
CNA
CTL0
CTL1
D0
D1
D2
D3
D4
D5
D6
D7
PD
LPS
NC
AGND
AGND
AVDD
AVDD
RESET
FILTER0
FILTER1
PLLVDD
PLLGND
PLLGND
XI
XO
DVDD
DVDD
DGND
DGND
TPB0−
AGND
AGND
TPBIAS1
TPA1+
TPA1−
TPB1+
TPB1−
AV DD
R1
R0
AGND
TPBIAS0
TPA0+
TPA0−
TPB0+
PAP PACKAGE
(TOP VIEW)
NOTE: Pin 16 (NC) could be tied to VDD for backward compatibility with the TSB41LV02A device.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
5
SLLS424F − JUNE 2000 − REVISED MARCH 2004
functional block diagram
CPS
LPS
ISO
CNA
SYSCLK
LREQ
CTL0
CTL1
D0
D1
D2
D3
D4
D5
D6
D7
Received Data
Decoder/Retimer
Link
Interface
I/O
TPA0+
TPA0−
Cable Port 0
TPB0+
Arbitration
and Control
State Machine
Logic
TPB0−
PC0
PC1
PC2
C/LKON
TPA1+
TPA1−
Cable Port 1
TPB1+
TPB1−
R0
R1
TPBIAS0
TPBIAS1
PD
RESET
6
Bias Voltage
and
Current
Generator
Transmit Data
Encoder
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
Crystal
Oscillator,
PLL System,
and Clock
Generator
XI
XO
FILTER0
FILTER1
SLLS424F − JUNE 2000 − REVISED MARCH 2004
Terminal Functions
TERMINAL
NAME
NO.
TYPE
I/O
DESCRIPTION
AGND
32, 33, 39,
48, 49, 50
Supply
−
Analog circuit ground terminals. These terminals should be tied together to the low impedance
circuit board ground plane.
AVDD
30, 31, 42,
51, 52
Supply
−
Analog circuit power terminals. A combination of high-frequency decoupling capacitors near each
terminal are suggested, such as paralleled 0.1 µF and 0.001 µF. Lower frequency 10-µF filtering
capacitors are also recommended. These supply terminals are separated from PLLVDD and
DVDD inside the device to provide noise isolation. They should be tied at a low-impedance point
on the circuit board.
19
CMOS
I/O
Bus manager contender programming input and link-on output. On hardware reset, this terminal
is used to set the default value of the contender status indicated during self-ID. Programming is
done by tying the terminal through a 10-kΩ resistor to a high (contender) or low (not contender).
The resistor allows the link-on output to override the input. However, it is recommended that this
terminal should be programmed low, and that the contender status be set via the C register bit.
C/LKON
If the TSB41AB2 is used with an LLC that has a dedicated terminal for monitoring LKON and also
setting the contender status, then a 1-kΩ series resistor should be placed on the LKON line
between the PHY and LLC to prevent bus contention.
Following hardware reset, this terminal is the link-on output, which is used to notify the LLC to
power up and become active. The link-on output is a square-wave signal with a period of
approximately 163 ns (8 SYSCLK cycles) when active. The link-on output is otherwise driven low,
except during hardware reset when it is high-impedance.
The link-on output is activated if the LLC is inactive (LPS inactive or the LCtrl bit cleared) and
when:
a) the PHY receives a link-on PHY packet addressed to this node, or
b) the PEI (port-event interrupt) register bit is 1, or
c) any of the CTOI (configuration-time-out interrupt), CPSI
(cable-power-status interrupt), or STOI (state-time-out interrupt)
register bits are 1 and the RPIE (resuming-port interrupt enable)
register bit is also 1.
Once activated, the link-on output continues active until the LLC becomes active (both LPS active
and the LCtrl bit set). The PHY also deasserts the link-on output when a bus reset occurs unless
the link-on output would otherwise be active because one of the interrupt bits is set (that is, the
link-on output is active due solely to the reception of a link-on PHY packet).
NOTE: If an interrupt condition exists which would otherwise cause the link-on output to be
activated if the LLC were inactive, the link-on output is activated when the LLC subsequently
becomes inactive.
CNA
3
CMOS
O
Cable-not-active output. This terminal is asserted high when there are no ports receiving
incoming bias voltage. CNA is not valid at initial power up, until a device hard reset is performed.
CPS
24
CMOS
I
Cable power status input. This terminal is normally connected to cable power through a 400-kΩ
resistor. This circuit drives an internal comparator that is used to detect the presence of cable
power. This terminal should be tied directly to DVDD supply through a 1-kΩ resistor if application
does not require it to be used.
CTL0
CTL1
4
5
CMOS
I/O
Control I/Os. These bidirectional signals control communication between the TSB41AB2 and the
LLC. Bus holders are built into these terminals.
D0
D1
D2
D3
D4
D5
D6
D7
6
7
8
9
10
11
12
13
CMOS
I/O
Data I/Os. These are bidirectional data signals between the TSB41AB2 and the LLC. Bus holders
are built into these terminals.
17, 18, 63,
64
Supply
−
Digital circuit ground terminals. These terminals should be tied together to the low-impedance
circuit board ground plane.
DGND
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
7
SLLS424F − JUNE 2000 − REVISED MARCH 2004
Terminal Functions (Continued)
TERMINAL
TYPE
I/O
DESCRIPTION
25, 26, 61,
62
Supply
−
Digital circuit power terminals. A combination of high frequency decoupling capacitors near each
terminal is suggested, such as paralleled 0.1 µF and 0.001 µF. Lower frequency 10-µF filtering
capacitors are also recommended. These supply terminals are separated from PLLVDD and AVDD
inside the device to provide noise isolation. They should be tied at a low-impedance point on the
circuit board.
FILTER0
FILTER1
54
55
CMOS
I/O
PLL filter terminals. These terminals are connected to an external capacitor to form a lag-lead filter
required for stable operation of the internal frequency multiplier PLL running from the crystal
oscillator. A 0.1-µF ±10% capacitor is the only external component required to complete this filter.
ISO
23
CMOS
I
Link interface isolation control input. This terminal controls the operation of output differentiation
logic on the CTL and D terminals. If an optional Annex J type isolation barrier is implemented
between the TSB41AB2 and LLC, the ISO terminal should be tied low to enable the differentiation
logic. If no isolation barrier is implemented (direct connection), or TI bus holder isolation is
implemented, the ISO terminal should be tied high through a pullup to disable the differentiation
logic. For additional information refer to TI application note Galvanic Isolation of the IEEE
1394−1995 Serial Bus, literature number SLLA011.
LPS
15
CMOS
I
Link power status input. This terminal is used to monitor the active/power status of the link layer
controller and to control the state of the PHY−LLC interface. This terminal should be connected
through a 10-kΩ resistor either to the VDD supplying the LLC, or to a pulsed output which is active
when the LLC is powered (see Figure 8). A pulsed signal should be used when an isolation barrier
exists between the LLC and PHY (see Figure 9).
NAME
DVDD
NO.
The LPS input is considered inactive if it is sampled low by the PHY for more than 2.6 µs (128
SYSCLK cycles), and is considered active otherwise (that is, asserted steady high or an
oscillating signal with a low time less than 2.6 µs). The LPS input must be high for at least 21 ns
to assure that a high is observed by the PHY.
When the TSB41AB2 detects that LPS is inactive, it places the PHY-LLC interface into a
low-power reset state. In the reset state, the CTL and D outputs are held in the logic zero state
and the LREQ input is ignored; however, the SYSCLK output remains active. If the LPS input
remains low for more than 26 µs (1280 SYSCLK cycles), the PHY-LLC interface is put into a
low-power disabled state in which the SYSCLK output is also held inactive. The PHY-LLC
interface is placed into the disabled state upon hardware reset.
The LLC is considered active only if both the LPS input is active and the LCtrl register bit is set
to 1, and is considered inactive if either the LPS input is inactive or the LCtrl register bit is cleared
to 0.
8
LREQ
1
CMOS
I
LLC request input. The LLC uses this input to initiate a service request to the TSB41AB2. Bus
holder is built into this terminal.
PC0
PC1
PC2
20
21
22
CMOS
I
Power class programming inputs. On hardware reset, these inputs set the default value of the
power class indicated during self-ID. Programming is done by tying these terminals high or low.
See Table 9 for encoding.
PD
14
CMOS
I
Power-down input. A high on this terminal turns off all internal circuitry except the cable-active
monitor circuits, which control the CNA output. Asserting the PD input high also activates an
internal pulldown on the RESET terminal so as to force a reset of the internal control logic. (PD
is provided for legacy compatibility and is not recommended power management in place of IEEE
1394a-2000 suspend/resume LPS and C/LKON features.)
PLLGND
57, 58
Supply
−
PLL circuit ground terminals. These terminals should be tied together to the low-impedance circuit
board ground plane.
PLLVDD
56
Supply
−
PLL circuit power terminals. A combination of high-frequency decoupling capacitors near each
terminal is suggested, such as paralleled 0.1 µF and 0.001 µF. Lower frequency 10-µF filtering
capacitors are also recommended. This supply terminal is separated from DVDD and AVDD inside
the device to provide noise isolation. It should be tied at a low-impedance point on the circuit
board.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SLLS424F − JUNE 2000 − REVISED MARCH 2004
Terminal Functions (Continued)
TERMINAL
NAME
NO.
TYPE
I/O
DESCRIPTION
R0
R1
40
41
Bias
−
Current setting resistor terminals. These terminals are connected through an external resistor to
set the internal operating currents and cable driver output currents. A resistance of 6.34 kΩ ±1.0%
is required to meet the IEEE Std 1394-1995 output voltage limits.
RESET
53
CMOS
I
Logic reset input. Asserting this terminal low resets the internal logic. An internal pullup resistor
to VDD is provided so only an external delay capacitor is required for proper power-up operation
(see power-up reset in the Application Information section). The RESET terminal also
incorporates an internal pulldown which is activated when the PD input is asserted high. This input
is otherwise a standard logic input, and may also be driven by an open-drain type driver.
SE
28
CMOS
I
Test control input. This input is used in manufacturing test of the TSB41AB2. For normal use this
terminal may be tied to GND through a 1-kΩ pulldown resistor or it may be tied to GND directly.
SM
29
CMOS
I
Test control input. This input is used in manufacturing test of the TSB41AB2. For normal use this
terminal should be tied to GND.
SYSCLK
2
CMOS
O
System clock output. Provides a 49.152-MHz clock signal, synchronized with data transfers, to
the LLC.
TESTM
27
CMOS
I
Test control input. This input is used in manufacturing test of the TSB41AB2. For normal use this
terminal should be tied to VDD through a 1-kΩ resistor.
TPA0+
TPA1+
37
46
Cable
I/O
TPA0−
TPA1−
36
45
Cable
I/O
Twisted-pair cable A differential signal terminals. Board traces from each pair of positive and
negative differential signal terminals should be kept matched and as short as possible to the
external load resistors and to the cable connector. For an unused port, TPA+ and TPA− can be
left open.
TPB0+
TPB1+
35
44
Cable
I/O
TPB0−
TPB1−
34
43
Cable
I/O
TPBIAS0
TPBIAS1
38
47
Cable
I/O
Twisted-pair bias output. This provides the 1.86-V nominal bias voltage needed for proper
operation of the twisted-pair cable drivers and receivers, and for signaling to the remote nodes
that there is an active cable connection. Each of these terminals, except for an unused port, must
be decoupled with a 1-µF capacitor to ground. For the unused port, this terminal can be left
unconnected.
XI
XO
59
60
Crystal
−
Crystal oscillator inputs. These terminals connect to a 24.576-MHz parallel resonant fundamental
mode crystal. The optimum values for the external shunt capacitors are dependent on the
specifications of the crystal used (see crystal selection in the Application Information section).
When an external clock source is used, XI should be the input and XO should be left open, and
the clock must be supplied before the device is taken out of reset.
Twisted-pair cable B differential signal terminals. Board traces from each pair of positive and
negative differential signal terminals should be kept matched and as short as possible to the
external load resistors and to the cable connector. For an unused port, TPB+ and TPB− can be
left open.
NOTE: It is strongly recommended that signals tied to VDD use a 1-kΩ resistor (minimum). Tying signals directly to VCC may result in ESD failures.
Signals tied to ground may be tied directly.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
9
SLLS424F − JUNE 2000 − REVISED MARCH 2004
absolute maximum ratings over operating free-air temperature (unless otherwise noted)†
Supply voltage range, VDD (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 V to 4 V
Input voltage range, VI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.5 V to VDD + 0.5 V
Output voltage range at any output, VO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.5 V to VDD + 0.5V
Continuous total power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Dissipation Rating Table
Operating free air temperature, TA, TSB41AB2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to 70°C
TSB41AB2I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −40°C to 85°C
Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −65°C to 150°C
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260°C
† Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under recommended operating conditions is not implied.
Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
NOTE 1: All voltage values, except differential I/O bus voltages, are with respect to network ground.
DISSIPATION RATING TABLE
PACKAGE
PAP§
PAP¶
TA ≤ 25°C
POWER RATING
DERATING FACTOR‡
ABOVE TA = 25°C
TA = 70°C
POWER RATING
4.78 W
38 mW/_C
3.06 W
2.5 W
2.13 W
17 mW/_C
1.36 W
1.11 W
1.33 W
1.1 W
PAP#
2.08 W
16 mW/_C
‡ This is the inverse of the traditional junction-to-ambient thermal resistance (RθJA).
§ 1 oz. trace and copper pad with solder.
¶ 1 oz. trace and copper pad without solder.
# Standard JEDEC low-K board.
TA = 85°C
POWER RATING
For more information, refer to TI technical brief PowerPAD Thermally Enhanced Package, TI literature
number SLMA002.
10
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SLLS424F − JUNE 2000 − REVISED MARCH 2004
recommended operating conditions
TYP†
MIN
Source power node
Supply voltage, VDD
TSB41AB2
Nonsource power node
TSB41AB2I
LREQ, CTL0, CTL1, D0 −D7
High-level input voltage, VIH
3
2.7‡
3‡
Output current, IO
Maximum junction temperature, TJ
(see RθJA
JA values listed in thermal
characteristics table)
Differential input voltage, VID
3.6
3
3.6
3.3
3.6
2.6
V
V
RESET
0.6 VDD
V
1.2
V
C/LKON, PC0, PC1, PC2, ISO, PD
0.2 VDD
V
RESET
0.3 VDD
V
TPBIAS outputs
−5.6
1.3
RθJA
JA = 26.10°C/W
TA = 70°C
TA = 85°C
RθJA
JA = 58.57°C/W
TA = 70°C
TA = 85°C
112.3
RθJA
JA = 60.08°C/W
TA = 70°C
TA = 85°C
113.1
97.2
97.4
118
260
Cable inputs, during arbitration
168
265
2.515
2.015‡
0.4706
TPB cable inputs, nonsource power node
0.4706
Power-up reset time, t(pu)
RESET input
2
V
± 1.08
± 0.5
TPA, TPB cable inputs, S400 operation
± 0.315
Between TPA and TPB cable inputs, S100 operation
± 0.8
Between TPA and TPB cable inputs, S200 operation
± 0.55
Between TPA and TPB cable inputs, S400 operation
† All typical values are at VDD = 3.3 V and TA = 25°C.
‡ For a node that does not source power; see Section 4.2.2.2 in IEEE 1394a-2000.
± 0.5
• DALLAS, TEXAS 75265
mV
ms
TPA, TPB cable inputs, S200 operation
POST OFFICE BOX 655303
°C
98.2
Cable inputs, during data reception
TPA, TPB cable inputs, S100 operation
mA
82.2
TPB cable inputs, source power node
Receive input skew
V
0.7 VDD
Common-mode input voltage, VIC
Receive input jitter
3.3
UNIT
C/LKON, PC0, PC1, PC2, ISO, PD
LREQ, CTL0, CTL1, D0 −D7
Low-level input voltage, VIL
MAX
ns
ns
11
SLLS424F − JUNE 2000 − REVISED MARCH 2004
electrical characteristics over recommended ranges of operating conditions (unless otherwise
noted)
driver
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Differential output voltage
56 Ω, see Figure 1
172
265
mV
IDIFF
Driver difference current, TPA+, TPA−, TPB+, TPB−
Drivers enabled, speed
signaling off
−1.05†
1.05†
mA
ISP200
ISP400
Common mode speed signaling current, TPB+, TPB−
S200 speed signaling enabled
S400 speed signaling enabled
−2.53‡
−8.1‡
mA
Common mode speed signaling current, TPB+, TPB−
−4.84‡
−12.4‡
VOD
mA
VOFF
Off state differential voltage
Drivers disabled, See Figure 1
20
mV
† Limits defined as algebraic sum of TPA+ and TPA− driver currents. Limits also apply to TPB+ and TPB− algebraic sum of driver currents.
‡ Limits defined as absolute limit of each of TPB+ and TPB− driver currents
receiver
PARAMETER
zid
TEST CONDITIONS
Differential impedance
MIN
TYP
4
7
Drivers disabled
MAX
UNIT
kΩ
4
20
pF
kΩ
zic
Common-mode impedance
Drivers disabled
24
pF
VTH−R
VTH−CB
Receiver input threshold voltage
Drivers disabled
−30
30
mV
Cable bias detect threshold, TPB cable inputs
Drivers disabled
0.6
1
V
VTH+
Positive arbitration comparator threshold voltage
Drivers disabled
89
168
mV
VTH−
Negative arbitration comparator threshold
voltage
Drivers disabled
−168
−89
mV
VTH−SP200
Speed signal threshold
TPBIAS−TPA common-mode voltage,
drivers disabled
49
131
mV
VTH−SP400
Speed signal threshold
TPBIAS−TPA common-mode voltage,
drivers disabled
314
396
mV
12
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SLLS424F − JUNE 2000 − REVISED MARCH 2004
electrical characteristics over recommended ranges of operating conditions (unless otherwise
noted) (continued)
device
PARAMETER
IDD
TEST CONDITIONS
Supply current
MIN
TYP
See Note 2
71
See Note 3
69
See Note 4
59
MAX
UNIT
mA
IDD(ULP)
Supply current, ultralow-power mode
VDD = 3.3 V, TA = 25°C,
Port disabled, PD = 0 V,
LPS = 0 V
IDD(PD)
Supply current, power-down mode
PD = VDD,
TA = 25°C
V(TH)
Power status threshold, CPS input†
400-kΩ resistor†
4.7
High-level output voltage, CTL0, CTL1,
D0 −D7, CNA, C/LKON, SYSCLK outputs
VDD = 2.7 V, IOH = − 4 mA
VDD = 3 V to 3.6 V,
IOH = − 4 mA
2.2
VOH
VOL
Low-level output voltage, CTL0, CTL1,
D0 −D7, CNA, C/LKON, SYSCLK outputs
IOL = 4 mA
VOH(AJ)
High-level Annex J output voltage, CTL0,
CTL1, D0 −D7, C/LKON, SYSCLK outputs
Annex J: IOH = − 9 mA,
ISO = 0 V,
VDD ≥ 3 V
VOL(AJ)
Low-level Annex J output voltage, CTL0,
CTL1, D0−D7, C/LKON, SYSCLK outputs
Annex J: IOL = 9 mA,
ISO = 0 V,
VDD ≥ 3 V
I(BH+)
Positive peak bus holder current, D0 −D7,
CTL0 −CTL1, LREQ
ISO = 3.6 V, VDD = 3.6 V,
VI = 0 V to VDD
0.05
1
mA
I(BH−)
Negative peak bus holder current,
D0 −D7, CTL0 −CTL1, LREQ
ISO = 3.6 V, VDD = 3.6 V,
VI = 0 V to VDD
−1.0
−0.05
mA
II
Input current, LREQ, LPS, PD, TESTM,
SM, PC0 – PC2 inputs
ISO = 0 V,
5
µA
IOZ
Off-state output current, CTL0, CTL1,
D0 – D7, C/LKON I/Os
VO = VDD or 0 V
±5
µA
−90
−20
µA
5
50
µA
I(IRST)
I(SE_Pd)
VIT+
VIT −
Pullup current, RESET input
VDD = 3.3 V,
µA
150
µA
7.5
VDD−0.4
Positive input threshold voltage, LREQ,
CTL0, CTL1, D0 – D7 inputs
ISO = 0 V,
Positive input threshold voltage, LPS
inputs
ISO = 0 V, VDD = 3 V to 3.6 V
Vref = 0.42 VDD
Negative input threshold voltage, LREQ,
CTL0, CTL1, D0 – D7 inputs
ISO= 0 V,
Negative input threshold voltage, LPS
inputs
ISO= 0 V, Vref = 0.42 VDD,
VDD = 3 V to 3.6 V
VDD = 3V to 3.6 V
VDD = 3 V to 3.6 V
VDD/2+0.3
V
V
0.4
VDD = 3.6 V
V
V
2.8
0.4
VI = 1.5 V or 0 V
VI = VDD/2 or VDD
Pulldown current, SE input
150
V
VDD/2+0.9
V
VREF+1
VDD/2−0.9
VDD/2−0.3
V
Vref+0.2
VO
TPBIAS output voltage‡
At rated IO current
1.665
2.015
V
† Measured at cable power side of resistor
‡ TPBIAS is close to VDD when the port is not connected.
NOTES: 2. Transmit maximum packet (all ports transmitting maximum size isochronous packet – 4096 bytes, sent on every isochronous
interval, S400, data value of CCCCCCCCh), VDD = 3.3 V, TA = 25°C.
3. Repeat typical packet (receiving on one port DV packets on every isochronous interval, S100, and transmitting on the other port),
VDD = 3.3 V, TA = 25°C.
4. Idle (one port receiving and one port transmitting cycle starts), VDD = 3.3 V, TA = 25°C.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
13
SLLS424F − JUNE 2000 − REVISED MARCH 2004
thermal characteristics
TEST CONDITIONS†
PARAMETER
RθJA
Junction-to-ambient thermal resistance
RθJC
Junction-to-case-thermal resistance
RθJA
Junction-to-ambient thermal resistance
RθJC
Junction-to-case thermal resistance
RθJA
Junction-to-ambient thermal resistance
MIN
Board mounted, no air flow, high conductivity
TI-recommended test board, chip soldered or
greased to thermal land with 1 oz. copper
TYP
MAX
UNIT
26
°C/W
5.9
Board mounted, no air flow, high conductivity
TI-recommended test board with thermal land, but no
solder or grease thermal connection to thermal land
with 1 oz. copper
58.57
Board mounted, no air flow, low conductivity JEDEC
test board with 1 oz. copper
60.08
°C/W
5.9
RθJC
Junction-to-case thermal resistance
† Use of thermally enhanced PowerPad PAP package is assumed in all three test conditions.
°C/W
5.9
switching characteristics
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Jitter, transmit
Between TPA and TPB
± 0.15
ns
Skew, transmit
Between TPA and TPB
± 0.1
ns
th
tsu
Hold time, CTL0, CTL1, D0 – D7, LREQ after SYSCLK
50% to 50%, See Figure 2
2
ns
Setup time, CTL0, CTL1, D0 – D7, LREQ to SYSCLK
50% to 50%, See Figure 2
Delay time, SYSCLK to CTL0, CTL1, D0 – D7
50% to 50%, See Figure 3
5
2‡
ns
td
tr
TP differential rise time, transmit
10% to 90%, at 1394 connector
0.5
1.2
ns
90% to 10%, at 1394 connector
0.5
1.2
ns
tf
TP differential fall time, transmit
‡ Test Conditions: 3.3 VCC, TA = 25°C
14
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
ns
SLLS424F − JUNE 2000 − REVISED MARCH 2004
PARAMETER MEASUREMENT INFORMATION
TPA+
TPB+
56 Ω
TPA−
TPB−
Figure 1. Test Load Diagram
SYSCLK
th
tsu
Dx, CTLx,
LREQ
Figure 2. Dx, CTLx, LREQ Input Setup and Hold Time Waveforms
SYSCLK
td
Dx, CTLx
Figure 3. Dx and CTLx Output Delay Relative to SYSCLK Waveforms
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
15
SLLS424F − JUNE 2000 − REVISED MARCH 2004
APPLICATION INFORMATION
component connection
Details regarding connection of components to the various terminals of the TSB41AB2 are discussed primarily
in entries for each terminal in the terminal functions table. Figure 4 is a diagrammatic view showing the
connections for all required external components.
1 µF
6.34 kΩ
±1 %
TPBIAS
TP Cables
Interface
Connection †
1 µF
TPBIAS
60
61
VDD
62
0.1
µF
0.001 µF
63
TPA0+
TPBIAS0
R0
AGND
R1
AVDD
TPB1−
TPA1−
TPB1+
TPA1+
TPBIAS1
CPS
PLLGND
ISO
XI
PC2
XO
PC1
DVDD
PC0
DVDD
C/LKON
DGND
DGND
DGND
LREQ
64
PLLGND
2
3
4
5
6
7
8
9
CNA OUT
1
DGND
† See Figure 5, Figure 6, and Figure 7.
‡ See Figure 8 and Figure 9.
NC
12
pF
24.576 MHz
DVDD
LPS
59
12
pF
DVDD
PLLVDD
PD
58
FILTER1
10 11 12 13 14 15 16
POWER DOWN
57
TESTM
D7
0.001 µF
FILTER0
D6
0.1
µF
SE
D5
56
RESET
D4
VDD
55
SM
D3
54
0.1 µF
AVDD
AVDD
D2
53
AVDD
D1
0.1 µF
AGND
AVDD
D0
52
36 35 34 33
AGND
CTL1
51
AGND
CTL0
VDD
50
CNA
0.001
µF
SYSCLK
49
0.001
µF
0.1
µF
AGND
48 47 46 45 44 43 42 41 40 39 38 37
AGND
TP Cables
Interface
Connection †
TPB0−
VDD
0.001
µF
TPA0−
0.001
µF
TPB0+
0.1 µF
‡
Figure 4. External Component Connections
16
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
32
0.001 µF
31
0.1 µF
0.001 µF
30
VDD
29
1 kΩ (Optional)
28
27
1 kΩ
VDD
0.001
µF
26
25
24
23
0.001
µF
400 kΩ
Cable Power
ISO
22
21
20
Power-Class
Programming
LKON
Bus Manager
19
18
17
0.1
µF
10 kΩ
DGND
SLLS424F − JUNE 2000 − REVISED MARCH 2004
APPLICATION INFORMATION
Outer Shield
Termination
TSB41AB2
400 kΩ
CPS
TPBIAS
56 Ω‡
1 µF
Cable
Power
Pair
56 Ω‡
TPA+
Cable
Pair
A
TPA−
Cable Port
TPB+
Cable
Pair
B
TPB−
56 Ω‡
56 Ω‡
220 pF†
5 kΩ
† The IEEE Std 1394-1995 calls for a 250-pF capacitor, which is a nonstandard component value. A 220-pF capacitor is recommended.
‡ ± 0.5% to meet 1394−1995 specification.
Figure 5. TP Cable Connections
Outer Cable Shield
1 MΩ
0.01 µF
0.001 µF
Chassis GND
Figure 6. Compliant DC Isolated Outer Shield Termination
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
17
SLLS424F − JUNE 2000 − REVISED MARCH 2004
APPLICATION INFORMATION
Outer Shield Termination
Chassis GND
Figure 7. Nonisolated Outer Shield Termination
10 kΩ
Link Power
LPS
Square Wave Input
LPS
10 kΩ
Figure 8. Nonisolated Circuit Connection Variations for LPS
PHY VDD
13.7 kΩ
LPS
Square Wave Signal
0.033 µF
10 kΩ
PHY GND
NOTE: As long as the resistance ratio is maintained between 1.61:1 and
1.33:1, any values of resistors may be used.
Figure 9. Isolated Circuit Connection for LPS
crystal selection
The TSB41AB2 and other TI PHY devices are designed to use an external 24.576-MHz crystal connected
between the XI and XO terminals to provide the reference for an internal oscillator circuit. This oscillator in turn
drives a PLL circuit that generates the various clocks required for transmission and resynchronization of data
at the S100 through S400 media data rates.
A variation of less than ± 100 ppm from nominal for the media data rates is required by IEEE Std 1394. Adjacent
PHYs may therefore have a difference of up to 200 ppm from each other in their internal clocks, and PHYs must
be able to compensate for this difference over the maximum packet length. Larger clock variations may cause
resynchronization overflows or underflows, resulting in corrupted packet data.
For the TSB41AB2, the SYSCLK output may be used to measure the frequency accuracy and stability of the
internal oscillator and PLL from which it is derived. The frequency of the SYSCLK output must be within
± 100 ppm of the nominal frequency of 49.152 MHz.
18
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SLLS424F − JUNE 2000 − REVISED MARCH 2004
APPLICATION INFORMATION
crystal selection (continued)
The following are some typical specifications for crystals used with the physical layers from TI in order to achieve
the required frequency accuracy and stability:
D Crystal mode of operation: Fundamental
D Frequency tolerance at 25°C: Total frequency variation for the complete circuit is 100 ppm. A crystal with
± 30-ppm frequency tolerance is recommended for adequate margin.
D Frequency stability (over temperature and age): A crystal with ±30-ppm frequency stability is recommended
for adequate margin.
NOTE: The total frequency variation must be kept below ± 100 ppm from nominal with some allowance for
error introduced by board and device variations. Trade-offs between frequency tolerance and stability may
be made as long as the total frequency variation is less than ± 100 ppm. For example, the frequency
tolerance of the crystal may be specified at 50 ppm and the temperature tolerance may be specified at 30
ppm to give a total of 80 ppm possible variation due to the crystal alone. Crystal aging also contributes to the
frequency variation.
D Load capacitance: For parallel resonant mode crystal circuits, the frequency of oscillation is dependent
upon the load capacitance specified for the crystal. Total load capacitance (CL) is a function of not only the
discrete load capacitors, but also board layout and circuit. It may be necessary to intermittently select
discrete load capacitors until the SYSCLK output is within specification. It is recommended that load
capacitors with a maximum of ± 5% tolerance be used.
As an example, for the OHCI + 41LV02 + evaluation module (EVM), which uses a crystal specified for 12-pF
loading, load capacitors (C9 and C10 in Figure 10) of 16 pF each were appropriate for the layout of that particular
board. The load specified for the crystal includes the load capacitors (C9, C10), the loading of the PHY terminals
[C(PHY)] and the loading of the board itself [C(BD)]. The value of C(PHY) is typically about 1 pF, and C(BD) is
typically 0.8 pF per centimeter of board etch; a typical board can have 3 pF to 6 pF or more. The load capacitors
C9 and C10 combine as capacitors in series so that the total load capacitance is:
C +
L
C9 C10 )
ƪ((C9
ƫ ) C(PHY) ) C(BD)
) C10)
(1)
C9
XI
24.576 MHz
X1
C(PHY) + C(BD)
XO
C10
Figure 10. Load Capacitance for the TSB41AB2 PHY
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
19
SLLS424F − JUNE 2000 − REVISED MARCH 2004
APPLICATION INFORMATION
crystal selection (continued)
The layout of the crystal portion of the PHY circuit is important for obtaining the correct frequency, minimizing
noise introduced into the PHY phase-lock loop, and minimizing any emissions from the circuit. The crystal and
two load capacitors should be considered as a unit during layout. The crystal and load capacitors should be
placed as close as possible to one another while minimizing the loop area created by the combination of the
three components. Varying the size of the capacitors may help in this. Minimizing the loop area minimizes the
effect of the resonant current (Is) that flows in this resonant circuit. This layout unit (crystal and load capacitors)
should then be placed as close as possible to the PHY XI and XO terminals to minimize trace lengths. Figure 11
depicts a layout that meets these guidelines.
C9
C10
X1
Figure 11. Recommended Crystal and Capacitor Layout
It is strongly recommended that part of the verification process for the design be to measure the frequency of
the SYSCLK output of the PHY. This should be done with a frequency counter with an accuracy of six digits or
better. If the SYSCLK frequency is more than the crystal tolerance from 49.152 MHz, the load capacitance of
the crystal may be varied to improve frequency accuracy. If the frequency is too high, add more load
capacitance; if the frequency is too low, decrease load capacitance. Typically, changes should be done to both
load capacitors (C9 and C10 above) at the same time, and both should be of the same value. Additional design
details and requirements may be provided by the crystal vendor. For more information, see Selection and
Specification of Crystals for Texas Instruments IEEE 1394 Physical Layers, TI literature number SLLA051.
EMI guidelines
For electromagnetic interference (EMI) guidelines and recommendations, send a request via email to:
[email protected]
designing with the PowerPAD package
The TSB41AB2 is housed in a high performance, thermally enhanced, 64-terminal PAP PowerPAD package.
Use of the PowerPAD package does not require any special considerations except to note that the PowerPAD,
which is an exposed metallic pad on the bottom of the device, is a thermal and electrical conductor. This exposed
pad is connected inside the package to the substrate of the silicon die, it is not connected to any terminal of the
package. Therefore, if not implementing PowerPAD PCB features, the use of solder masks (or other assembly
techniques) may be required to prevent any inadvertent shorting by the exposed PowerPAD of connection
etches or vias under the package. The recommended option, however, is to not run any etches or signal vias
under the device, but to have only a grounded thermal land as explained below. Although the actual size of the
exposed die pad may vary, the minimum size required for the keep-out area of the 64-terminal PAP PowerPAD
package is 8 mm × 8 mm.
It is recommended that there be a thermal land, which is an area of solder-tinned-copper (see Figure 12),
underneath the PowerPAD package. The thermal land varies in size depending on the PowerPAD package
being used, the PCB construction, and the amount of heat that needs to be removed. In addition, the thermal
land may or may not contain numerous thermal vias depending on PCB construction.
20
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SLLS424F − JUNE 2000 − REVISED MARCH 2004
APPLICATION INFORMATION
designing with the PowerPAD package (continued)
Other requirements for thermal lands and thermal vias are detailed in PowerPAD Thermally Enhanced Package
Technical Brief, TI literature number SLMA002, available via the TI Web pages beginning at URL
http://www.ti.com.
Figure 12. Example of a Thermal Land for the TSB41AB2PAP PHY
For the TSB41AB2, this thermal land should be grounded to the low impedance ground plane of the device. This
improves not only thermal performance but also the electrical grounding of the device. It is also recommended
that the device ground terminal landing pads be connected directly to the grounded thermal land. The land size
should be as large as possible without shorting device signal terminals. The thermal land may be soldered to
the exposed PowerPAD using standard reflow soldering techniques.
While the thermal land may be electrically floated and configured to remove heat to an external heat sink, it is
recommended that the thermal land be connected to the low-impedance ground plane for the device. More
information may be obtained from the TI application report Recommendations for PHY Layout, TI literature
number SLLA020.
internal register configuration
There are 16 accessible internal registers in the TSB41AB2. The configuration of the registers at addresses 0h
through 7h (the base registers) is fixed, while the configuration of the registers at addresses 8h through Fh (the
paged registers) is dependent upon which one of eight pages, numbered 0 through 7, is currently selected. The
selected page is set in base register 7.
The configuration of the base registers is shown in Table 1, and corresponding field descriptions are given in
Table 2. The base register field definitions are unaffected by the selected page number.
A reserved register or register field (marked as Reserved or Rsvd in register configuration tables) is read as 0,
but is subject to future usage. All registers in pages 2 through 6 are reserved.
Table 1. Base Register Configuration
ADDRESS
BIT POSITION
0
1
2
0000
0001
3
4
RHB
IBR
Extended (111b)
0011
PHY_Speed (010b)
Rsvd
Jitter (000b)
0100
LCtrl
C
0101
RPIE
ISBR
6
7
R
CPS
Gap_Count
0010
Num_Ports (00010b)
CTOI
CPSI
0110
0111
5
Physical ID
Delay (0000b)
Pwr_Class
STOI
PEI
EAA
EMC
Reserved
Page_Select
POST OFFICE BOX 655303
Rsvd
• DALLAS, TEXAS 75265
Port_Select
21
SLLS424F − JUNE 2000 − REVISED MARCH 2004
APPLICATION INFORMATION
Table 2. Base Register Field Descriptions
SIZE
TYPE
DESCRIPTION
Physical ID
FIELD
6
Rd
This field contains the physical address ID of this node determined during self-ID. The physical ID is invalid
after a bus reset until self-ID has completed as indicated by an unsolicited register-0 status transfer.
R
1
Rd
Root. This bit indicates that this node is the root node. The R bit is reset to 0 by bus reset, and is set to 1
during tree-ID if this node becomes root.
CPS
1
Rd
Cable-power status. This bit indicates the state of the CPS input terminal. The CPS terminal is normally tied
to serial bus cable power through a 400-kΩ resistor. A 0 in this bit indicates that the cable power voltage
has dropped below its threshold for assured reliable operation.
RHB
1
Rd/Wr
Root-holdoff bit. This bit instructs the PHY to attempt to become root after the next bus reset. The RHB bit
is reset to 0 by hardware reset and is unaffected by bus reset.
IBR
1
Rd/Wr
Initiate bus-reset. This bit instructs the PHY to initiate a long (166 µs) bus reset at the next opportunity. Any
receive or transmit operation in progress when this bit is set completes before the bus reset is initiated. The
IBR bit is reset to 0 by hardware reset or bus reset.
Gap_Count
6
Rd/Wr
Arbitration gap count. This value is used to set the subaction (fair) gap, arb-reset gap, and arb-delay times.
The gap count may be set either by a write to this register or by reception or transmission of a PHY_CONFIG
packet. The gap count is set to 3Fh by hardware reset or after two consecutive bus resets without an
intervening write to the gap count register (either by a write to the PHY register or by a PHY_CONFIG
packet).
Extended
3
Rd
Extended register definition. For the TSB41AB2 this field is 111b, indicating that the extended register set
is implemented.
Num_Ports
5
Rd
Number of ports. This field indicates the number of ports implemented in the PHY. For the TSB41AB2 this
field is 2.
PHY_Speed
3
Rd
PHY speed capability. For the TSB441AB2 PHY this field is 010b, indicating S400 speed capability.
Delay
4
Rd
PHY repeater data delay. This field indicates the worst case repeater data delay of the PHY, expressed as
144+(delay × 20) ns. For the TSB41AB2 this field is 0.
LCtrl
1
Rd/Wr
Link-active status control. This bit is used to control the active status of the LLC as indicated during self-ID.
The logical AND of this bit and the LPS active status is replicated in the L field (bit 9) of the self-ID packet.
The LLC is considered active only if both the LPS input is active and the LCtrl bit is set.
The LCtrl bit provides a software controllable means to indicate the LLC active status in lieu of using the LPS
input. The LCtrl bit is set to 1 by hardware reset and is unaffected by bus reset.
NOTE: The state of the PHY-LLC interface is controlled solely by the LPS input, regardless of the state of
the LCtrl bit. If the PHY-LLC interface is operational as determined by the LPS input being active, then
received packets and status information continues to be presented on the interface, and any requests
indicated on the LREQ input is processed, even if the LCtrl bit is cleared to 0.
C
1
Rd/Wr
Contender status. This bit indicates that this node is a contender for the bus or isochronous resource
manager. This bit is replicated in the c field (bit 20) of the self-ID packet. This bit is set to the state specified
by the C/LKON input terminal upon hardware reset and is unaffected by bus reset.
Jitter
3
Rd
PHY repeater jitter. This field indicates the worst case difference between the fastest and slowest repeater
data delay, expressed as (JITTER+1) × 20 ns. For the TSB41AB2 this field is 0.
Pwr_Class
3
Rd/Wr
Node power class. This field indicates this node’s power consumption and source characteristics, and is
replicated in the pwr field (bits 21– 23) of the self-ID packet. This field is set to the state specified by the
PC0– PC2 input terminals upon hardware reset and is unaffected by bus reset (see Table 9).
22
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SLLS424F − JUNE 2000 − REVISED MARCH 2004
APPLICATION INFORMATION
Table 2. Base Register Field Descriptions (Continued)
FIELD
SIZE
TYPE
DESCRIPTION
RPIE
1
Rd/Wr
Resuming port interrupt enable. This bit, if set to 1, enables the port event interrupt (PEI) bit to be set
whenever resume operations begin on any port. This bit also enables the C/LKON output signal to be
activated whenever the LLC is inactive and any of the CTOI, CPSI, or STOI interrupt bits are set. This bit is
reset to 0 by hardware reset and is unaffected by bus reset.
ISBR
1
Rd/Wr
Initiate short arbitrated bus reset. This bit, if set to 1, instructs the PHY to initiate a short (1.3 µs) arbitrated
bus reset at the next opportunity. This bit is reset to 0 by bus reset.
NOTE: Legacy IEEE Std 1394-1995 compliant PHYs may not be capable of performing short bus resets.
Therefore, initiation of a short bus reset in a network that contains such a legacy device results in a long bus
reset being performed.
CTOI
1
Rd/Wr
Configuration time-out interrupt. This bit is set to 1 when the arbitration controller times out during tree-ID
start, and may indicate that the bus is configured in a loop. This bit is reset to 0 by hardware reset, or by writing
a 1 to this register bit.
If the CTOI and RPIE bits are both set and the LLC is or becomes inactive, the PHY activates the C/LKON
output to notify the LLC to service the interrupt.
NOTE: If the network is configured in a loop, only those nodes that are part of the loop generate a
configuration time-out interrupt. All other nodes instead time out waiting for the tree-ID and/or self-ID process
to complete and then generate a state time-out interrupt and bus reset.
CPSI
1
Rd/Wr
Cable power status interrupt. This bit is set to 1 whenever the CPS input transitions from high to low indicating
that cable power may be too low for reliable operation. This bit is reset to 1 by hardware reset. It can be
cleared by writing a 1 to this register bit.
If the CPSI and RPIE bits are both set and the LLC is or becomes inactive, the PHY activates the C/LKON
output to notify the LLC to service the interrupt.
STOI
1
Rd/Wr
State time-out interrupt. This bit indicates that a state time-out has occurred (which also causes a bus reset
to occur). This bit is reset to 0 by hardware reset, or by writing a 1 to this register bit. If the STOI and RPIE
bits are both set and the LLC is or becomes inactive, the PHY activates the C/LKON output to notify the LLC
to service the interrupt.
PEI
1
Rd/Wr
Port event interrupt. This bit is set to 1 upon a change in the bias, connected, disabled, or fault bits for any
port for which the port interrupt enable (PIE) bit is set. Additionally, if the resuming port interrupt enable (RPIE)
bit is set, the PEI bit is set to 1 at the start of resume operations on any port. This bit is reset to 0 by hardware
reset, or by writing a 1 to this register bit.
If the PEI bit is set (regardless of the state of the RPEI bit) and the LLC is or becomes inactive, the PHY
activates the C/LKON output to notify the LLC to service the interrupt.
EAA
1
Rd/Wr
Enable accelerated arbitration. This bit enables the PHY to perform the various arbitration acceleration
enhancements defined in IEEE 1394a-2000 (ACK-accelerated arbitration, asynchronous fly-by
concatenation, and isochronous fly-by concatenation). This bit is reset to 0 by hardware reset and is
unaffected by bus reset.
NOTE: The EAA bit should be set only if the attached LLC is IEEE 1394a-2000 compliant. If the LLC is not
IEEE 1394a-2000 compliant, use of the arbitration acceleration enhancements may interfere with
isochronous traffic by excessively delaying the transmission of cycle-start packets.
EMC
1
Rd/Wr
Enable multispeed concatenated packets. This bit enables the PHY to transmit concatenated packets of
differing speeds in accordance with the protocols defined in IEEE 1394a-2000. This bit is reset to 0 by
hardware reset and is unaffected by bus reset.
NOTE: The use of multispeed concatenation is completely compatible with networks containing legacy IEEE
Std 1394-1995 PHYs. However, use of multispeed concatenation requires that the attached LLC be IEEE
1394a-2000 compliant.
Page_Select
3
Rd/Wr
Page select. This field selects the register page to use when accessing register addresses 8 through 15. This
field is reset to 0 by hardware reset and is unaffected by bus reset.
Port_Select
4
Rd/Wr
Port select. This field selects the port when accessing per-port status or control (for example, when one of
the port status/control registers is accessed in page 0). Ports are numbered starting at 0. This field is reset
to 0 by hardware reset and is unaffected by bus reset.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
23
SLLS424F − JUNE 2000 − REVISED MARCH 2004
APPLICATION INFORMATION
The port status page provides access to configuration and status information for each of the ports. The port is
selected by writing 0 to the Page_Select field and the desired port number to the Port_Select field in base
register 7. The configuration of the port status page registers is shown in Table 3, and corresponding field
descriptions are given in Table 4. If the selected port is unimplemented, all registers in the port status page are
read as 0.
Table 3. Page 0 (Port Status) Register Configuration
BIT POSITION
ADDRESS
1000
1001
24
0
1
2
Astat
3
4
5
Ch
Con
PIE
Fault
Bstat
Peer_Speed
1010
Reserved
1011
Reserved
1100
Reserved
1101
Reserved
1110
Reserved
1111
Reserved
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
6
7
Bias
Dis
Reserved
SLLS424F − JUNE 2000 − REVISED MARCH 2004
APPLICATION INFORMATION
Table 4. Page 0 (Port Status) Register Field Descriptions
SIZE
TYPE
Astat
FIELD
2
Rd
TPA line state. This field indicates the TPA line state of the selected port, encoded as follows:
Code
Line State
11
Z
01
1
10
0
00
invalid
DESCRIPTION
Bstat
2
Rd
TPB line state. This field indicates the TPB line state of the selected port. This field has the same
encoding as the Astat field.
Ch
1
Rd
Child/parent status. A 1 indicates that the selected port is a child port. A 0 indicates that the selected port
is the parent port. A disconnected, disabled, or suspended port is reported as a child port. The Ch bit
is invalid after a bus reset until tree-ID has completed.
Con
1
Rd
Debounced port connection status. This bit indicates that the selected port is connected. The connection
must be stable for the debounce time of approximately 341 ms for the con bit to be set to 1. The con bit
is reset to 0 by hardware reset and is unaffected by bus reset.
NOTE: The con bit indicates that the port is physically connected to a peer PHY, but the port is not
necessarily active.
Bias
1
Rd
Debounced incoming cable bias status. A 1 indicates that the selected port is detecting incoming cable
bias. The incoming cable bias must be stable for the debounce time of 52 µs for the bias bit to be set
to 1.
Dis
1
Rd/Wr
Port disabled control. If 1, the selected port is disabled. The dis bit is reset to 0 by hardware reset (all
ports are enabled for normal operation following hardware reset). The dis bit is not affected by bus reset.
Peer_Speed
3
Rd
Port peer speed. This field indicates the highest speed capability of the peer PHY connected to the
selected port, encoded as follows:
Code
Peer Speed
000
S100
001
S200
010
S400
011–111
invalid
The Peer_Speed field is invalid after a bus-reset until self-ID has completed.
NOTE: Peer speed codes higher than 010b (S400) are defined in IEEE 1394a-2000. However, the
TSB41AB2 is only capable of detecting peer speeds up to S400.
PIE
1
Rd/Wr
Port event interrupt enable. When set to 1, a port event on the selected port sets the port event interrupt
(PEI) bit and notify the link. This bit is reset to 0 by hardware reset and is unaffected by bus reset.
Fault
1
Rd/Wr
Fault. This bit indicates that a resume-fault or suspend-fault has occurred on the selected port and that
the port is in the suspended state. A resume-fault occurs when a resuming port fails to detect incoming
cable bias from its attached peer. A suspend-fault occurs when a suspending port continues to detect
incoming cable bias from its attached peer. Writing 1 to this bit clears the bit to 0. This bit is reset to 0
by hardware reset and is unaffected by bus reset.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
25
SLLS424F − JUNE 2000 − REVISED MARCH 2004
APPLICATION INFORMATION
The vendor identification page is used to identify the vendor/manufacturer and compliance level. The page is
selected by writing 1 to the Page_Select field in base register 7. The configuration of the vendor identification
page is shown in Table 5, and corresponding field descriptions are given in Table 6.
Table 5. Page 1 (Vendor ID) Register Configuration
BIT POSITION
ADDRESS
0
1
2
3
4
1000
Compliance
1001
Reserved
1010
Vendor_ID[0]
1011
Vendor_ID[1]
1100
Vendor_ID[2]
1101
Product_ID[0]
1110
Product_ID[1]
1111
Product_ID[2]
5
6
7
Table 6. Page 1 (Vendor ID) Register Field Descriptions
SIZE
TYPE
DESCRIPTION
Compliance
FIELD
8
Rd
Compliance level. For the TSB41AB2 this field is 01h, indicating compliance with IEEE
1394a-2000.
Vendor_ID
24
Rd
Manufacturer’s organizationally unique identifier (OUI). For the TSB41AB2 this field is 08 0028h
(Texas Instruments) (the MSB is at register address 1010b).
Product_ID
24
Rd
Product identifier. For the TSB41AB2 this field is 42 XXXXh (the MSB is at register address
1101b).
The vendor-dependent page provides access to the special control features of the TSB41AB2, as well as
configuration and status information used in manufacturing test and debug. This page is selected by writing 7
to the Page_Select field in base register 7. The configuration of the vendor-dependent page is shown in Table 7,
and corresponding field descriptions are given in Table 8.
Table 7. Page 7 (Vendor-Dependent) Register Configuration
BIT POSITION
ADDRESS
1000
0
1
2
NPA
4
1001
Reserved for test
1010
Reserved for test
1011
Reserved for test
1100
Reserved for test
1101
Reserved for test
1110
SWR
Reserved for test
1111
26
3
Reserved
Reserved for test
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
5
6
7
Link_Speed
SLLS424F − JUNE 2000 − REVISED MARCH 2004
APPLICATION INFORMATION
Table 8. Page 7 (Vendor-Dependent) Register Field Descriptions
SIZE
TYPE
DESCRIPTION
NPA
FIELD
1
Rd/Wr
Null-packet actions flag. This bit instructs the PHY to not clear fair and priority requests when a null packet
is received with arbitration acceleration enabled. If 1, then fair and priority requests are cleared only when
a packet of more than 8 bits is received; ACK packets (exactly 8 data bits), null packets (no data bits), and
malformed packets (less than 8 data bits) do not clear fair and priority requests. If 0, then fair and priority
requests are cleared when any non-ACK packet is received, including null packets or malformed packets
of less than 8 bits. This bit is cleared to 0 by hardware reset and is unaffected by bus reset.
Link_Speed
2
Rd/Wr
Link speed. This field indicates the top speed capability of the attached LLC. Encoding is as follows:
Code
Speed
00
S100
01
S200
10
S400
11
illegal
This field is replicated in the sp field of the self-ID packet to indicate the speed capability of the node (PHY
and LLC in combination). However, this field does not affect the PHY speed capability indicated to peer
PHYs during self-ID; the TSB41AB2 PHY identifies itself as S400 capable to its peers regardless of the
value in this field. This field is set to 10b (S400) by hardware reset and is unaffected by bus reset.
SWR
1
Rd/Wr
Software hard reset. Writing a 1 to this bit forces a hard reset of the PHY (just as momentarily asserting
the RESET terminal low). This bit is always read as a 0.
power-class programming
The PC0– PC2 terminals are programmed to set the default value of the power class indicated in the pwr field
(bits 21 – 23) of the transmitted self-ID packet. Descriptions of the various power classes are given in Table 9.
The default power-class value is loaded following a hardware reset, but is overridden by any value subsequently
loaded into the Pwr_Class field in register 4.
Table 9. Power Class Descriptions
PC0 – PC2
DESCRIPTION
000
Node does not need power and does not repeat power.
001
Node is self-powered and provides a minimum of 15 W to the bus.
010
Node is self-powered and provides a minimum of 30 W to the bus.
011
Node is self-powered and provides a minimum of 45 W to the bus.
100
Node may be powered from the bus for the PHY only using up to 3 W and may also provide power to the bus. The amount of
bus power that it provides can be found in the configuration ROM.
101
Reserved
110
Node is powered from the bus and uses up to 3 W. An additional 3 W is needed to enable the link.
111
Node is powered from the bus and uses up to 3 W. An additional 7 W is needed to enable the link.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
27
SLLS424F − JUNE 2000 − REVISED MARCH 2004
APPLICATION INFORMATION
using the TSB41AB2 with a non-IEEE 1394a-2000 link layer
The TSB41AB2 implements the PHY-LLC interface specified in IEEE 1394a-2000. This interface is based upon
the interface described in informative Annex J of IEEE Std 1394-1995, which is the interface used in older TI
PHY devices. The PHY-LLC interface specified in IEEE 1394a-2000 is completely compatible with the older
Annex J interface.
IEEE 1394a-2000 includes enhancements to the Annex J interface that must be comprehended when using
the TSB41AB2 with a non-IEEE 1394a-2000 LLC device.
D A new LLC service request was added which allows the LLC to temporarily enable and disable
asynchronous arbitration accelerations. If the LLC does not implement this new service request, the
arbitration enhancements should not be enabled (see the EAA bit in PHY register 5).
D The capability to perform multispeed concatenation (the concatenation of packets of differing speeds) was
added in order to improve bus efficiency (primarily during isochronous transmission). If the LLC does not
support multispeed concatenation, multispeed concatenation should not be enabled in the PHY (see the
EMC bit in PHY register 5).
D In order to accommodate the higher transmission speeds expected in future revisions of the standard, IEEE
1394a-2000 extended the speed code in bus requests from 2 bits to 3 bits, increasing the length of the bus
request from 7 bits to 8 bits. The new speed codes were carefully selected so that new IEEE 1394a-2000
PHY and LLC devices would be compatible, for speeds from S100 to S400, with legacy PHY and LLC
devices that use the 2-bit speed codes. The TSB41AB2 correctly interprets both 7-bit bus requests (with
2-bit speed codes) and 8-bit bus requests (with 3-bit speed codes). Moreover, if a 7-bit bus request is
immediately followed by another request (for example, a register read or write request), the TSB41AB2
correctly interprets both requests. Although the TSB41AB2 correctly interprets 8-bit bus requests, a request
with a speed code exceeding S400 results in the TSB41AB2 transmitting a null packet (data-prefix followed
by data-end, with no data in the packet).
More explanation is included in the TI application note IEEE 1394a Features Supported by TI TSB41LV0X
Physical Layer Devices, TI literature number SLLA019.
using the TSB41AB2 with a lower-speed link layer
Although the TSB41AB2 is an S400 capable PHY, it may be used with lower speed LLCs, such as the S200
capable TSB12LV31. In such a case, the LLC has fewer data terminals than the PHY, and some Dn terminals
on the TSB41AB2 remain unused. Unused Dn terminals should be pulled to ground through 10-kΩ resistors.
The TSB41AB2 transfers all received packet data to the LLC, even if the speed of the packet exceeds the
capability of the LLC to accept it. Some lower speed LLC designs do not properly ignore packet data in such
cases. On the rare occasions that the first 16 bits of partial data accepted by such an LLC match the bus ID and
node ID for that node, spurious header CRC or tcode errors may result.
During bus initialization following a bus reset, each PHY transmits a self-ID packet that indicates, among other
information, the speed capability of the PHY. The bus manager (if one exists) builds a speed map from the
collected self-ID packets. This speed map gives the highest possible speed that can be used on the
node-to-node communication paths between every pair of nodes in the network.
28
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SLLS424F − JUNE 2000 − REVISED MARCH 2004
APPLICATION INFORMATION
using the TSB41AB2 with a lower-speed link layer (continued)
In the case of a node consisting of a higher-speed PHY and a lower-speed LLC, the speed capability of the node
(PHY and LLC in combination) is that of the lower-speed LLC. A sophisticated bus manager may be able to
determine the LLC speed capability by reading the configuration ROM Bus_Info_Block, or by sending
asynchronous request packets at different speeds to the node and checking for an acknowledge; the speed map
may then be adjusted accordingly. The speed map should reflect that communication to such a node must be
done at the lower speed of the LLC, instead of the higher speed of the PHY. However, speed-map entries for
paths that merely pass through the node PHY, but do not terminate at that node, should not be restricted by the
lower speed of the LLC.
To assist in building an accurate speed map, the TSB41AB2 has the capability of indicating a speed capability
other than S400 in its transmitted self-ID packet. This is controlled by the Link_Speed field in register 8 of the
vendor-dependent page (page 7). Setting the Link_Speed field affects only the speed indicated in the self-ID
packet; it has no effect on the speed signaled to peer PHYs during self-ID. The TSB41AB2 identifies itself as
S400 capable to its peers regardless of the value in the Link_Speed field.
Generally, the Link_Speed field should not be changed from its power-on default value of S400 unless it is
determined that the speed map (if one exists) is incorrect for path entries terminating in the local node. If the
speed map is incorrect, it can be assumed that the bus manager has used only the self-ID packet information
to build the speed map. In this case, the node may update the Link_Speed field to reflect the lower speed
capability of the LLC and then initiate another bus reset to cause the speed map to be rebuilt. Note that in this
scenario any speed map entries for node-to-node communication paths that pass through the local node’s PHY
are restricted by the lower speed.
In the case of a leaf node (which has only one active port) the Link_Speed field may be set to indicate the speed
of the LLC without first checking the speed map. Changing the Link_Speed field in a leaf node can only affect
those paths that terminate at that node; because no other paths can pass through a leaf node it can have no
effect on other paths in the speed map. For hardware configurations, which can only be a leaf node (all ports
but one are unimplemented), it is recommended that the Link_Speed field be updated immediately after
power-on or hardware reset.
power-up reset
To ensure proper operation of the TSB41AB2 the RESET terminal must be asserted low for a minimum of 2 ms
from the time that PHY power reaches the minimum required supply voltage. When using a passive capacitor
on the RESET terminal to generate a power-on reset signal, the minimum reset time is assured if the capacitor
has a minimum value of 0.1 µF and also satisfies the following equation:
C
min
+ 0.0077
T ) 0.085
(2)
where Cmin is the minimum capacitance on the RESET terminal in µF, and T is the VDD ramp time, 10%– 90%,
in milliseconds.
bus reset
In the TSB41AB2, the initiate bus reset (IBR) bit may be set to 1 in order to initiate a bus reset and initialization
sequence. The IBR bit is located in PHY register 1, along with the root-holdoff bit (RHB) and gap-count register,
as required by IEEE 1394a-2000 (this configuration also maintains compatibility with older TI PHY designs
which were based upon the suggested register set defined in Annex J of IEEE Std 1394-1995). Therefore,
whenever the IBR bit is written, the RHB and gap count are also necessarily written.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
29
SLLS424F − JUNE 2000 − REVISED MARCH 2004
APPLICATION INFORMATION
bus reset (continued)
The RHB and gap count may also be updated by PHY-config packets. The TSB41AB2 is IEEE 1394a-2000
compliant, and therefore both the reception and transmission of PHY-config packets cause the RHB and gap
count to be loaded, unlike older IEEE Std 1394-1995 compliant PHYs which decode only received PHY-config
packets.
The gap count is set to the maximum value of 63 after two consecutive bus resets without an intervening write
to the gap count, either by a write to PHY register 1 or by a PHY-config packet. This mechanism allows a
PHY-config packet to be transmitted and then a bus reset initiated so as to verify that all nodes on the bus have
updated their RHBs and gap-count values, without having the gap count set back to 63 by the bus reset. The
subsequent connection of a new node to the bus, which initiates a bus reset, then causes the gap count of each
node to be set to 63. Note, however, that if a subsequent bus reset is instead initiated by a write to register 1
to set the IBR bit, all other nodes on the bus have their gap-count values set to 63, while this node gap count
remains set to the value just loaded by the write to PHY register 1.
Therefore, in order to maintain consistent gap counts throughout the bus, the following rules apply to the use
of the IBR bit, RHB, and gap-count in PHY register 1:
D Following the transmission of a PHY-config packet, a bus reset must be initiated in order to verify that all
nodes have correctly updated their RHBs and gap-count values, and to ensure that a subsequent new
connection to the bus causes the gap count to be set to 63 on all nodes in the bus. If this bus reset is initiated
by setting the IBR bit to 1, the RHB and gap-count register must also be loaded with the correct values
consistent with the just transmitted PHY-config packet. In the TSB41AB2, the RHB and gap count are
updated to their correct values upon the transmission of the PHY-config packet, and so these values may
first be read from register 1 and then rewritten.
D Other than to initiate the bus reset which must follow the transmission of a PHY-config packet, whenever
the IBR bit is set to 1 in order to initiate a bus reset, the gap-count value must also be set to 63 so as to be
consistent with other nodes on the bus, and the RHB should be maintained with its current value.
D The PHY register 1 should not be written to except to set the IBR bit. The RHB and gap count should not
be written without also setting the IBR bit to 1.
30
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SLLS424F − JUNE 2000 − REVISED MARCH 2004
PRINCIPLES OF OPERATION
PHY-Link layer interface
The TSB41AB2 is designed to operate with an LLC such as the Texas Instruments TSB12LV21, TSB12LV22,
TSB12LV23, TSB12LV26, TSB12LV31, TSB12LV41, TSB12LV42 or TSB12LV01A. Details of operation for the
Texas Instruments LLC devices are found in the respective LLC data sheets. The following paragraphs describe
the operation of the PHY-LLC interface.
The interface to the LLC consists of the SYSCLK, CTL0 – CTL1, D0 – D7, LREQ, LPS, C/LKON, and ISO
terminals on the TSB41AB2, as shown in Figure 13.
Link
Layer
Controller
TSB41AB2
SYSCLK
CTL0−CTL1
D1−D7
LREQ
LPS
C/LKON
ISO
ISO
ISO
Figure 13. PHY-LLC Interface
The SYSCLK terminal provides a 49.152-MHz interface clock. All control and data signals are synchronized to,
and sampled on, the rising edge of SYSCLK.
The CTL0 and CTL1 terminals form a bidirectional control bus, which controls the flow of information and data
between the TSB41AB2 and LLC.
The D0 – D7 terminals form a bidirectional data bus, which is used to transfer status information, control
information, or packet data between the devices. The TSB41AB2 supports S100, S200, and S400 data transfers
over the D0 – D7 data bus. In S100 operation only the D0 and D1 terminals are used; in S200 operation only
the D0 – D3 terminals are used; and in S400 operation all D0 – D7 terminals are used for data transfer. When
the TSB41AB2 is in control of the D0 – D7 bus, unused Dn terminals are driven low during S100 and S200
operations. When the LLC is in control of the D0– D7 bus, unused Dn terminals are ignored by the TSB41AB2.
The LREQ terminal is controlled by the LLC to send serial service requests to the PHY in order to request access
to the serial bus for packet transmission, read or write PHY registers, or control arbitration acceleration.
The LPS and C/LKON terminals are used for power management of the PHY and LLC. The LPS terminal
indicates the power status of the LLC, and may be used to reset the PHY-LLC interface or to disable SYSCLK.
The C/LKON terminal is used to send a wake-up notification to the LLC and to indicate an interrupt to the LLC
either when LPS is inactive or when the PHY register LCtrl bit is zero.
The ISO terminal is used to enable the output differentiation logic on the CTL0 – CTL1 and D0 – D7 terminals.
Output differentiation is required when an Annex J type isolation barrier is implemented between the PHY and
LLC.
The TSB41AB2 normally controls the CTL0– CTL1 and D0– D7 bidirectional buses. The LLC is allowed to drive
these buses only after the LLC has been granted permission to do so by the PHY.
There are four operations that may occur on the PHY-LLC interface: link service request, status transfer, data
transmit, and data receive. The LLC issues a service request to read or write a PHY register, to request the PHY
to gain control of the serial bus in order to transmit a packet, or to control arbitration acceleration.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
31
SLLS424F − JUNE 2000 − REVISED MARCH 2004
PRINCIPLES OF OPERATION
PHY-Link layer interface (continued)
The PHY may initiate a status transfer either autonomously or in response to a register read request from the
LLC.
The PHY initiates a receive operation whenever a packet is received from the serial bus.
The PHY initiates a transmit operation after winning control of the serial bus following a bus request by the LLC.
The transmit operation is initiated when the PHY grants control of the interface to the LLC.
The encoding of the CTL0 −CTL1 bus is shown in Table 10 and Table 11.
Table 10. CTL Encoding When PHY Has Control of the Bus
CTL0
CTL1
NAME
0
0
Idle
DESCRIPTION
0
1
Status
1
0
Receive
1
1
Grant
No activity (this is the default mode)
Status information is being sent from the PHY to the LLC.
An incoming packet is being sent from the PHY to the LLC.
The LLC has been given control of the bus to send an outgoing packet.
Table 11. CTL Encoding When LLC Has Control of the Bus
CTL0
CTL1
NAME
DESCRIPTION
0
0
Idle
The LLC releases the bus (transmission has been completed).
0
1
Hold
The LLC is holding the bus while data is being prepared for transmission, or indicating that another packet
is to be transmitted (concatenated) without arbitrating.
1
0
Transmit
An outgoing packet is being sent from the LLC to the PHY.
1
1
Reserved
None
output differentiation
When an Annex J type isolation barrier is implemented between the PHY and LLC, the CTL0– CTL1, D0 – D7,
and LREQ signals must be digitally differentiated so that the isolation circuits function correctly. Digital
differentiation is enabled on the TSB41AB2 when the ISO terminal is low.
The differentiation operates such that the output is driven either low or high for one clock period whenever the
signal changes logic state, but otherwise places the output in a high-impedance state for as long as the signal
logic state remains constant. On input, hysteresis buffers are used to convert the signal to the correct logic state
when the signal is high impedance; the biasing network of the Annex J type isolation circuit pulls the signal
voltage level between the hysteresis thresholds of the input buffer so that the previous logic state is maintained.
The correspondence between the output logic state and the output signal level is shown in Figure 14.
Logic State
0
1
1
0
0
0
1
0
0
L
H
Z
O
Z
Z
H
L
Z
Signal Level
Figure 14. Signal Transformation for Digital Differentiation
32
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SLLS424F − JUNE 2000 − REVISED MARCH 2004
PRINCIPLES OF OPERATION
output differentiation (continued)
The TSB41AB2 implements differentiation circuitry functionally equivalent to that shown in Figure 15 on the
bidirectional CTL0– CTL1and D0– D7 terminals. The TSB41AB2 also implements an input hysteresis buffer on
the LREQ input to convert this signal to the correct logic level when differentiated. The LLC must also implement
similar output differentiation and input hysteresis circuitry on its CTL and D terminals, and output differentiation
circuitry on its LREQ terminal.
Input Buffer With
Hysteresis
DIN
Q
D
D Terminal
DOUT
D
Q
To/From
Internal
Device Logic
3-State Output
Driver
ISO
D
OUTEN
Q
INIT
SYSCLK
Figure 15. Input/Output Differentiation Logic
LLC service request
To request access to the bus, to read or write a PHY register, or to control arbitration acceleration, the LLC sends
a serial bit stream on the LREQ terminal as shown in Figure 16.
LR0
LR1
LR2
LR3
LR(n-2)
LR(n-1)
NOTE: Each cell represents one clock sample time, and n is the number of bits in the request stream.
Figure 16. LREQ Request Stream
The length of the stream varies depending on the type of request as shown in Table 12.
Table 12. Request Stream Bit Length
REQUEST TYPE
Bus request
NUMBER OF BITS
7 or 8
Read register request
9
Write register request
17
Acceleration control request
6
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
33
SLLS424F − JUNE 2000 − REVISED MARCH 2004
PRINCIPLES OF OPERATION
LLC service request (continued)
Regardless of the type of request, a start bit of 1 is required at the beginning of the stream, and a stop bit of 0
is required at the end of the stream. The second through fourth bits of the request stream indicate the type of
the request. In the descriptions below, bit 0 is the most significant and is transmitted first in the request bit stream.
The LREQ terminal is normally low.
Encoding for the request type is shown in Table 13.
Table 13. Request Type Encoding
LR1 – LR3
NAME
DESCRIPTION
000
ImmReq
Immediate bus request. Upon detection of idle, the PHY takes control of the bus immediately without arbitration.
001
IsoReq
Isochronous bus request. Upon detection of idle, the PHY arbitrates for the bus without waiting for a subaction gap.
010
PriReq
Priority bus request. The PHY arbitrates for the bus after a subaction gap, ignores the fair protocol.
011
FairReq
Fair bus request. The PHY arbitrates for the bus after a subaction gap, follows the fair protocol.
100
RdReg
The PHY returns the specified register contents through a status transfer.
101
WrReg
Write to the specified register.
110
AccelCtl
Enable or disable asynchronous arbitration acceleration.
111
Reserved
Reserved.
For a bus request the length of the LREQ bit stream is 7 or 8 bits as shown in Table 14.
Table 14. Bus Request
BIT(S)
NAME
0
Start bit
1−3
Request type
4−6
Request speed
7
Stop bit
DESCRIPTION
Indicates the beginning of the transfer (always 1).
Indicates the type of bus request. See Table 13.
Indicates the speed at which the PHY sends the data for this request. See Table 15 for the encoding of this field.
Indicates the end of the transfer (always 0). If bit 6 is 0, this bit may be omitted.
The 3-bit request speed field used in bus requests is shown in Table 15.
Table 15. Bus Request
LR4 – LR6
DATA RATE
000
S100
010
S200
100
S400
All Others
Invalid
NOTE: The TSB41AB2 does accept a bus request with
an invalid speed code and process the bus
request normally. However, during packet
transmission for such a request, the TSB41AB2
ignores any data presented by the LLC and
transmits a null packet.
34
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SLLS424F − JUNE 2000 − REVISED MARCH 2004
PRINCIPLES OF OPERATION
LLC service request (continued)
For a read register request the length of the LREQ bit stream is 9 bits as shown in Table 16.
Table 16. Read Register Request
BIT(S)
NAME
0
Start bit
DESCRIPTION
1 −3
Request type
4 −7
Address
Identifies the address of the PHY register to be read
8
Stop bit
Indicates the end of the transfer (always 0)
Indicates the beginning of the transfer (always 1)
A 100 indicating this is a read register request
For a write register request the length of the LREQ bit stream is 17 bits as shown in Table 17.
Table 17. Write Register Request
BIT(S)
NAME
DESCRIPTION
0
Start bit
1 −3
Request type
Indicates the beginning of the transfer (always 1)
4 −7
Address
8−15
Data
A 101 indicating this is a write register request
Identifies the address of the PHY register to be written to
Gives the data that is to be written to the specified register address
For an acceleration control request the length of the LREQ bit stream is 6 bits as shown in Table 18.
Table 18. Acceleration Control Request
BIT(S)
NAME
0
Start bit
DESCRIPTION
1 −3
Request type
4
Control
Asynchronous period arbitration acceleration is enabled if 1, and disabled if 0.
5
Stop bit
Indicates the end of the transfer (always 0)
Indicates the beginning of the transfer (always 1)
A 110 indicating this is an acceleration control request
For fair or priority access, the LLC sends the bus request (FairReq or PriReq) at least one clock after the
PHY-LLC interface becomes idle. If the CTL terminals are asserted receive (10b) by the PHY, then any pending
fair or priority request is lost (cleared). Additionally, the PHY ignores any fair or priority requests if receive is
asserted while the LLC is sending the request. The LLC may then reissue the request one clock after the next
interface idle.
The cycle master node uses a priority bus request (PriReq) to send a cycle start message. After receiving or
transmitting a cycle start message, the LLC can issue an isochronous bus request (IsoReq). The PHY clears
an isochronous request only when the serial bus has been won.
To send an acknowledge packet, the LLC must issue an immediate bus request (ImmReq) during the reception
of the packet addressed to it. This is required in order to minimize the idle gap between the end of the received
packet and the start of the transmitted acknowledge packet. As soon as the receive packet ends, the PHY
immediately grants control of the bus to the LLC. The LLC sends an acknowledgment to the sender unless the
header CRC of the received packet is corrupted. In this case, the LLC does not transmit an acknowledge, but
instead cancels the transmit operation and releases the interface immediately; the LLC must not use this grant
to send another type of packet. After the interface is released the LLC may proceed with another request.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
35
SLLS424F − JUNE 2000 − REVISED MARCH 2004
PRINCIPLES OF OPERATION
LLC service request (continued)
The LLC may make only one bus request at a time. Once the LLC issues any request for bus access (ImmReq,
IsoReq, FairReq, or PriReq), it cannot issue another bus request until the PHY indicates that the bus request
was lost (bus arbitration lost and another packet received), or won (bus arbitration won and the LLC granted
control). The PHY ignores new bus requests while a previous bus request is pending. All bus requests are
cleared upon a bus reset.
For write register requests, the PHY loads the specified data into the addressed register as soon as the request
transfer is complete. For read register requests, the PHY returns the contents of the addressed register to the
LLC at the next opportunity through a status transfer. If a received packet interrupts the status transfer, then the
PHY continues to attempt the transfer of the requested register until it is successful. A write or read register
request may be made at any time, including while a bus request is pending. Once a read register request is
made, the PHY ignores further read register requests until the register contents are successfully transferred to
the LLC. A bus reset does not clear a pending read register request.
The TSB41AB2 includes several arbitration acceleration enhancements, which allow the PHY to improve bus
performance and throughput by reducing the number and length of interpacket gaps. These enhancements
include autonomous (fly-by) isochronous packet concatenation, autonomous fair and priority packet
concatenation onto acknowledge packets, and accelerated fair and priority request arbitration following
acknowledge packets. The enhancements are enabled when the EAA bit in PHY register 5 is set.
The arbitration acceleration enhancements may interfere with the ability of the cycle master node to transmit
the cycle start message under certain circumstances. The acceleration control request is therefore provided
to allow the LLC to temporarily enable or disable the arbitration acceleration enhancements of the TSB41AB2
during the asynchronous period. The LLC typically disables the enhancements when its internal cycle counter
rolls over indicating that a cycle start message is imminent, and then reenables the enhancements when it
receives a cycle start message. The acceleration control request may be made at any time, however, and is
immediately serviced by the PHY. Additionally, a bus reset or isochronous bus request causes the
enhancements to be reenabled, if the EAA bit is set.
status transfer
A status transfer is initiated by the PHY when there is status information to be transferred to the LLC. The PHY
waits until the interface is idle before starting the transfer. The transfer is initiated by the PHY asserting status
(01b) on the CTL terminals, along with the first two bits of status information on the D[0:1] terminals. The PHY
maintains CTL = status for the duration of the status transfer. The PHY may prematurely end a status transfer
by asserting something other than status on the CTL terminals. This occurs if a packet is received before the
status transfer completes. The PHY continues to attempt to complete the transfer until all status information has
been successfully transmitted. There is at least one idle cycle between consecutive status transfers.
The PHY normally sends just the first four bits of status to the LLC. These bits are status flags that are needed
by the LLC state machines. The PHY sends an entire 16-bit status packet to the LLC after a read register
request, or when the PHY has pertinent information to send to the LLC or transaction layers. The only defined
condition where the PHY automatically sends a register to the LLC is after self-ID, where the PHY sends the
physical-ID register that contains the new node address. All status transfers are either 4 or 16 bits unless
interrupted by a received packet. The status flags are considered to have been successfully transmitted to the
LLC immediately upon being sent, even if a received packet subsequently interrupts the status transfer. Register
contents are considered to have been successfully transmitted only when all 8 bits of the register have been
sent. A status transfer is retried after being interrupted only if any status flags remain to be sent, or if a register
transfer has not yet completed.
The definition of the bits in the status transfer is shown in Table 19, and the timing is shown in Figure 17.
36
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SLLS424F − JUNE 2000 − REVISED MARCH 2004
PRINCIPLES OF OPERATION
status transfer (continued)
Table 19. Status Bits
BIT(S)
NAME
DESCRIPTION
0
Arbitration reset gap
Indicates that the PHY has detected that the bus has been idle for an arbitration reset gap time (as defined
in IEEE Std 1394-1995). This bit is used by the LLC in the busy/retry state machine.
1
Subaction gap
Indicates that the PHY has detected that the bus has been idle for a subaction gap time (as defined in IEEE
Std 1394-1995). This bit is used by the LLC to detect the completion of an isochronous cycle.
2
Bus reset
Indicates that the PHY has entered the bus reset start state
3
Interrupt
Indicates that a PHY interrupt event has occurred. An interrupt event may be a configuration time-out,
cable-power voltage falling too low, a state time-out, or a port status change.
4 −7
Address
This field holds the address of the PHY register whose contents are being transferred to the LLC.
8 −15
Data
This field holds the register contents.
SYSCLK
(1)
(2)
00
CTL0, CTL1
00
01
D0, D1
00
S[0:1]
S[14:15]
00
Figure 17. Status Transfer Timing
The sequence of events for a status transfer is as follows:
1. Status transfer initiated. The PHY indicates a status transfer by asserting status on the CTL lines along with
the status data on the D0 and D1 lines (only two bits of status are transferred per cycle). Normally (unless
interrupted by a receive operation), a status transfer is either two or eight cycles long. A 2-cycle (4 bit)
transfer occurs when only status information is to be sent. An 8-cycle (16 bit) transfer occurs when register
data is to be sent in addition to any status information.
2. Status transfer terminated. The PHY normally terminates a status transfer by asserting idle on the CTL lines.
The PHY may also interrupt a status transfer at any cycle by asserting receive on the CTL lines to begin
a receive operation. The PHY asserts at least one cycle of idle between consecutive status transfers.
receive
Whenever the PHY detects the data-prefix state on the serial bus, it initiates a receive operation by asserting
receive on the CTL terminals and a logic 1 on each of the D terminals (data-on indication). The PHY indicates
the start of a packet by placing the speed code (encoded as shown in Table 20) on the D terminals, followed
by packet data. The PHY holds the CTL terminals in receive until the last symbol of the packet has been
transferred. The PHY indicates the end of packet data by asserting idle on the CTL terminals. All received
packets are transferred to the LLC. Note that the speed code is part of the PHY-LLC protocol and is not included
in the calculation of CRC or any other data protection mechanisms.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
37
SLLS424F − JUNE 2000 − REVISED MARCH 2004
PRINCIPLES OF OPERATION
receive (continued)
It is possible for the PHY to receive a null packet, which consists of the data-prefix state on the serial bus followed
by the data-end state, without any packet data. A null packet is transmitted whenever the packet speed exceeds
the capability of the receiving PHY, or whenever the LLC immediately releases the bus without transmitting any
data. In this case, the PHY asserts receive on the CTL terminals with the data-on indication (all 1s) on the D
terminals, followed by idle on the CTL terminals, without any speed code or data being transferred. In all cases,
the TSB41AB2 sends at least one data-on indication before sending the speed code or terminating the receive
operation.
The TSB41AB2 also transfers its own self-ID packet, transmitted during the self-ID phase of bus initialization,
to the LLC. This packet is transferred to the LLC just as any other received self-ID packet. Figure 18 is the
reception timing diagram for normal packets, and Figure 19 is the reception timing diagram for null packets.
SYSCLK
(1)
CTL0, CTL1
00
01
10
(2)
D0–D7
XX
FF (Data-On)
00
(3)
(4)
SPD
d0
(5)
dn
00
Figure 18. Normal Packet Reception Timing
The sequence of events for a normal packet reception is as follows:
1. Receive operation initiated. The PHY indicates a receive operation by asserting receive on the CTL lines.
Normally, the interface is Idle until receive is asserted. However, the receive operation may interrupt a status
transfer operation that is in progress so that the CTL lines may change from status to receive without an
intervening idle.
2. Data-on indication. The PHY asserts the data-on indication code on the D lines for one or more cycles
preceding the speed code.
3. Speed code. The PHY indicates the speed of the received packet by asserting a speed code on the D lines
for one cycle immediately preceding packet data. The link decodes the speed code on the first receive cycle
for which the D lines are not the data-on code. If the speed code is invalid, or indicates a speed higher than
that which the link is capable of handling, the link should ignore the subsequent data.
4. Receive data. Following the data-on indication (if any) and the speed code, the PHY asserts packet data
on the D lines with receive on the CTL lines for the remainder of the receive operation.
5. Receive operation terminated. The PHY terminates the receive operation by asserting idle on the CTL lines.
The PHY asserts at least one cycle of idle following a receive operation.
SYSCLK
(1)
CTL0, CTL1
00
01
10
00
(2)
D0–D7
XX
FF (Data-On)
Figure 19. Null Packet Reception Timing
38
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
(3)
00
SLLS424F − JUNE 2000 − REVISED MARCH 2004
PRINCIPLES OF OPERATION
receive (continued)
The sequence of events for a null packet reception is as follows:
1. Receive operation initiated. The PHY indicates a receive operation by asserting receive on the CTL lines.
Normally, the interface is idle until receive is asserted. However, the receive operation may interrupt a status
transfer operation that is in progress so that the CTL lines may change from status to receive without an
intervening idle.
2. Data-on indication. The PHY asserts the data-on indication code on the D lines for one or more cycles.
3. Receive operation terminated. The PHY terminates the receive operation by asserting idle on the CTL lines.
The PHY asserts at least one cycle of idle following a receive operation.
Table 20. Receive Speed Codes
D0 −D7
DATA RATE
00XX XXXX
S100
0100 XXXX
S200
0101 0000
S400
1YYY YYYY
data-on indication
NOTE: X = Output as 0 by PHY, ignored by LLC.
Y = Output as 1 by PHY, ignored by LLC.
transmit
When the LLC issues a bus request through the LREQ terminal, the PHY arbitrates to gain control of the bus.
If the PHY wins arbitration for the serial bus, the PHY-LLC interface bus is granted to the LLC by asserting the
grant state (11b) on the CTL terminals for one SYSCLK cycle, followed by idle for one clock cycle. The LLC then
takes control of the bus by asserting either idle (00b), hold (01b) or transmit (10b) on the CTL terminals. Unless
the LLC is immediately releasing the interface, the LLC may assert Idle for at most one clock before it must assert
either hold or transmit on the CTL terminals. The hold state is used by the LLC to retain control of the bus while
it prepares data for transmission. The LLC may assert hold for zero or more clock cycles (that is, the LLC need
not assert hold before transmit). The PHY asserts data prefix on the serial bus during this time.
When the LLC is ready to send data, the LLC asserts transmit on the CTL terminals as well as sending the first
bits of packet data on the D lines. A transmit is held on the CTL terminals until the last bits of data have been
sent. The LLC then asserts either hold or idle on the CTL terminals for one clock cycle, and then asserts idle
for one additional cycle before releasing the interface bus and placing its CTL and D terminals in a highimpedance state. The PHY then regains control of the interface bus.
The hold asserted at the end of packet transmission indicates to the PHY that the LLC requests to send another
packet (concatenated packet) without releasing the serial bus. The PHY responds to this concatenation request
by waiting the required minimum packet separation time and then asserting grant as before. This function may
be used to send a unified response after sending an acknowledge, or to send consecutive isochronous packets
during a single isochronous period. Unless multispeed concatenation is enabled, all packets transmitted during
a single bus ownership must be of the same speed (since the speed of the packet is set before the first packet).
If multi-speed concatenation is enabled (when the EMSC bit of PHY register 5 is set), the LLC must specify the
speed code of the next concatenated packet on the D terminals when it asserts hold on the CTL terminals at
the end of a packet. The encoding for this speed code is the same as the speed code that precedes received
packet data as given in Table 20.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
39
SLLS424F − JUNE 2000 − REVISED MARCH 2004
PRINCIPLES OF OPERATION
transmit (continued)
After sending the last packet for the current bus ownership, the LLC releases the bus by asserting idle on the
CTL terminals for two clock cycles. The PHY begins asserting idle on the CTL terminals one clock after sampling
idle from the link. Note that whenever the D and CTL terminals change direction between the PHY and the LLC,
there is an extra clock period allowed so that both sides of the interface can operate on registered versions of
the interface signals. Figure 20 is the transmission timing diagram for normal packets, and Figure 21 is the
transmission timing diagram for cancelled or null packets.
SYSCLK
(1)
CTL0, CTL1
00
11
(2)
00
00
(3)
01
(4)
(5)
10
01
00
d0
SPD
00
(7)
00
00
00
00
(6)
D0–D7
00
00
dn
Link Controls CTL and D
PHY CTL and D Outputs Are High Impedance
NOTE: SPD = Speed code, see Table 20
d0 −dn = Packet data
Figure 20. Normal Packet Transmission Timing
The sequence of events for a normal packet transmission is as follows:
1. Transmit operation initiated. The PHY asserts grant on the CTL lines followed by idle to hand over control
of the interface to the link so that the link may transmit a packet. The PHY releases control of the interface
(that is, it places its CTL and D outputs in a high-impedance state) following the idle cycle.
2. Optional idle cycle. The link may assert at most one idle cycle preceding assertion of either hold or transmit.
This idle cycle is optional; the link is not required to assert idle preceding either hold or transmit.
3. Optional hold cycles. The link may assert hold for up to 47 cycles preceding assertion of transmit. These
hold cycle(s) are optional; the link is not required to assert hold preceding transmit.
4. Transmit data. When data is ready to be transmitted, the link asserts transmit on the CTL lines along with
the data on the D lines.
5. Transmit operation terminated. The transmit operation is terminated by the link asserting hold or idle on the
CTL lines. The link asserts hold to indicate that the PHY is to retain control of the serial bus in order to
transmit a concatenated packet. The link asserts idle to indicate that packet transmission is complete and
the PHY may release the serial bus. The link then asserts idle for one more cycle following this cycle of hold
or idle before releasing the interface and returning control to the PHY.
6. Concatenated packet speed code. If multispeed concatenation is enabled in the PHY, the link asserts a
speed code on the D lines when it asserts hold to terminate packet transmission. This speed code indicates
the transmission speed for the concatenated packet that is to follow. The encoding for this concatenated
packet speed code is the same as the encoding for the received packet speed code (see Table 20). The
link may not concatenate an S100 packet onto any higher-speed packet.
7. After regaining control of the interface, the PHY asserts at least one cycle of idle before any subsequent
status transfer, receive operation, or transmit operation.
40
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SLLS424F − JUNE 2000 − REVISED MARCH 2004
PRINCIPLES OF OPERATION
transmit (continued)
SYSCLK
(1)
CTL0, CTL1
00
D0–D7
00
11
00
(2)
(3)
(4)
(5)
00
01
00
00
00
00
Link Controls CTL and D
PHY CTL and D Outputs Are High Impedance
Figure 21. Cancelled/Null Packet Transmission
The sequence of events for a cancelled/null packet transmission is as follows:
1. Transmit operation initiated. PHY asserts grant on the CTL lines followed by idle to hand over control of the
interface to the link.
2. Optional idle cycle. The link may assert at most one idle cycle preceding assertion of hold. This idle cycle
is optional; the link is not required to assert idle preceding hold.
3. Optional hold cycles. The link may assert hold for up to 47 cycles preceding assertion of idle. These hold
cycle(s) are optional; the link is not required to assert hold preceding Idle.
4. Null transmit termination. The null transmit operation is terminated by the link asserting two cycles of idle
on the CTL lines and then releasing the interface and returning control to the PHY. Note that the link may
assert idle for a total of three consecutive cycles if it asserts the optional first idle but does not assert hold.
(It is recommended that the link assert three cycles of idle to cancel a packet transmission if no cycles of
hold are asserted. This ensures that either the link or PHY controls the interface in all cycles.)
5. After regaining control of the interface, the PHY asserts at least one cycle of idle before any subsequent
status transfer, receive operation, or transmit operation.
interface reset and disable
The LLC controls the state of the PHY-LLC interface using the LPS signal. The interface may be placed into a
reset state, a disabled state, or be made to initialize and then return to normal operation. When the interface
is not operational (whether reset, disabled, or in the process of initialization) the PHY cancels any outstanding
bus request or register read request, and ignores any requests made via the LREQ line. Additionally, any status
information generated by the PHY is not queued, and thus does not cause a status transfer upon restoration
of the interface to normal operation.
The LPS signal may be either a level signal or a pulsed signal, depending upon whether the PHY-LLC interface
is a direct connection or is made across an isolation barrier. When an isolation barrier exists between the PHY
and LLC (whether of the TI bus-holder type or Annex J type) the LPS signal must be pulsed. In a direct
connection, the LPS signal may be either a pulsed or a level signal. Timing parameters for the LPS signal are
given in Table 21.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
41
SLLS424F − JUNE 2000 − REVISED MARCH 2004
PRINCIPLES OF OPERATION
interface reset and disable (continued)
Table 21. LPS Timing Parameters
PARAMETER
DESCRIPTION
MIN
MAX
UNIT
0.09
2.6
µs
0.021
2.6
µs
TLPSL
TLPSH
LPS low time (when pulsed)†
LPS high time (when pulsed)†
TLPS_DUTY
TLPS_RESET
LPS duty cycle (when pulsed)‡
20
55
%
Time for PHY to recognize LPS deasserted and reset the interface
2.6
2.68
µs
TLPS_DISABLE
Time for PHY to recognize LPS deasserted and disable the interface
26.03
26.11
µs
15
23§
µs
TRESTORE
Time to permit optional isolation circuits to restore during an interface reset
PHY not in low-power state
TCLK_ACTIVATE
Time for SYSCLK to be activated from reassertion of LPS
PHY in low-power state
5.3
60
ns
7.3
ms
† The specified TLPSL and TLPSH times are worst-case values appropriate for operation with the TSB41AB2. These values are broader than those
specified for the same parameters in IEEE 1394a-2000 (that is, an implementation of LPS that meets the requirements of IEEE 1394a-2000
operates correctly with the TSB41AB2).
‡ A pulsed LPS signal must have a duty cycle (ratio of TLPSH to cycle period) in the specified range to ensure proper operation when using an
isolation barrier on the LPS signal (for example, as shown in Figure 9).
§ The maximum value for TRESTORE does not apply when the PHY-LLC interface is disabled, in which case an indefinite time may elapse before
LPS is reasserted. Otherwise, in order to reset but not disable the interface it is necessary that the LLC ensure that LPS is deasserted for less
than TLPS_DISABLE.
The LLC requests that the interface be reset by deasserting the LPS signal and terminating all bus and request
activity. When the PHY observes that LPS has been deasserted for TLPS_RESET, it resets the interface. When
the interface is in the reset state, the PHY sets its CTL and D outputs in the logic 0 state and ignores any activity
on the LREQ signal. The timing for interface reset is shown in Figure 22 and Figure 23.
ISO
(low)
(3)
(1)
SYSCLK
CTL0, CTL1
D0−D7
(2)
LREQ
(4)
LPS
TLPS_RESET
TLPSL
TRESTORE
TLPSH
Figure 22. Interface Reset, ISO Low
42
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SLLS424F − JUNE 2000 − REVISED MARCH 2004
PRINCIPLES OF OPERATION
interface reset and disable (continued)
The sequence of events for resetting the PHY-LLC interface when it is in the differentiated mode of operation
(ISO terminal is low) is as follows:
1. 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.
2. LPS deasserted. The LLC deasserts the LPS signal and, within 1 µs, terminates any request or interface
bus activity, and places its LREQ, CTL, and D outputs into a high-impedance state (the LLC should
terminate any output signal activity such that signals end in a logic 0 state).
3. Interface reset. After TLPS_RESET time, the PHY determines that LPS is inactive, terminates any interface
bus activity, and places its CTL and D outputs into a high-impedance state (the PHY terminates any output
signal activity such that signals end in a logic 0 state). The PHY-LLC interface is now in the reset state.
4. Interface restored. After the minimum TRESTORE time, the LLC may again assert LPS active. (The minimum
TRESTORE interval provides sufficient time for the biasing networks used in Annex J type isolation barrier
circuits to stabilize and reach a quiescent state if the isolation barrier has somehow become unbalanced.)
When LPS is asserted, the interface is initialized.
ISO
(high)
(3)
(1)
SYSCLK
CTL0, CTL1
D0−D7
(2)
LREQ
(4)
LPS
TLPS_RESET
TRESTORE
Figure 23. Interface Reset, ISO High
The sequence of events for resetting the PHY-LLC interface when it is in the nondifferentiated mode of operation
(ISO terminal is high) is as follows:
1. Normal operation. Interface is operating normally, with LPS asserted, SYSCLK active, status and packet
data reception and transmission via the CTL and D lines, and request activity via the LREQ line. In
Figure 23, the LPS signal is shown as a nonpulsed level signal. However, it is permissible to use a pulsed
signal for LPS in a direct connection between the PHY and LLC; a pulsed signal is required when using an
isolation barrier (whether of the TI bus-holder type or Annex J type).
2. LPS deasserted. The LLC deasserts the LPS signal and, within 1 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.
3. Interface reset. After TLPS_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.
4. Interface restored. After the minimum TRESTORE time, the LLC may again assert LPS active. When LPS
is asserted, the interface is initialized.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
43
SLLS424F − JUNE 2000 − REVISED MARCH 2004
PRINCIPLES OF OPERATION
interface reset and disable (continued)
If the LLC continues to keep the LPS signal deasserted, it requests that the interface be disabled. The PHY
disables the interface when it observes that LPS has been deasserted for TLPS_DISABLE. When the interface
is disabled, the PHY sets its CTL and D outputs as stated above for interface reset, but also stops SYSCLK
activity. The interface is also placed into the disabled condition upon a hardware reset of the PHY. The timing
for interface disable is shown in Figure 24 and Figure 25.
When the interface is disabled, the PHY enters a low-power state if none of its ports is active.
ISO
(low)
(3)
(1)
(4)
SYSCLK
CTL0, CTL1
D0−D7
(2)
LREQ
LPS
TLPSL
TLPS_RESET
TLPSH
TLPS_DISABLE
Figure 24. Interface Disable, ISO Low
The sequence of events for disabling the PHY-LLC interface when it is in the differentiated mode of operation
(ISO terminal is low) is as follows:
1. 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.
2. LPS deasserted. The LLC deasserts the LPS signal and, within 1 µs, terminates any request or interface
bus activity, and places its LREQ, CTL, and D outputs into a high-impedance state (the LLC should
terminate any output signal activity such that signals end in a logic 0 state).
3. Interface reset. After TLPS_RESET time, the PHY determines that LPS is inactive, terminates any interface
bus activity, and places its CTL and D outputs into a high-impedance state (the PHY terminates any output
signal activity such that signals end in a logic 0 state). The PHY-LLC interface is now in the reset state.
4. Interface disabled. If the LPS signal remains inactive for TLPS_DISABLE time, the PHY terminates SYSCLK
activity by placing the SYSCLK output into a high-impedance state. The PHY-LLC interface is now in the
disabled state.
44
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SLLS424F − JUNE 2000 − REVISED MARCH 2004
PRINCIPLES OF OPERATION
interface reset and disable (continued)
ISO
(high)
(3)
(1)
(4)
SYSCLK
CTL0, CTL1
D0− D7
(2)
LREQ
LPS
TLPS_RESET
TLPS_DISABLE
Figure 25. Interface Disable, ISO High
The sequence of events for disabling the PHY-LLC interface when it is in the nondifferentiated mode of operation
(ISO terminal is high) is as follows:
1. 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.
2. LPS deasserted. The LLC deasserts the LPS signal and, within 1 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.
3. Interface reset. After TLPS_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.
4. Interface disabled. If the LPS signal remains inactive for TLPS_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.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
45
SLLS424F − JUNE 2000 − REVISED MARCH 2004
PRINCIPLES OF OPERATION
interface reset and disable (continued)
ISO (low)
7 Cycles
SYSCLK
5 ns, Min
10 ns, Max
(3)
CTL0
(4)
(2)
CTL1
D0−D7
LREQ
(1)
LPS
TCLK_ACTIVE
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:
1. 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
reactivating the LPS signal. In Figure 26 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.
2. SYSCLK activated. If the interface is disabled, the PHY reactivates its SYSCLK output when it detects that
LPS has been reasserted. If the PHY has entered a low-power state, it takes between 5.3 ms to 7.3 ms for
SYSCLK to be restored; if the PHY is not in a low-power state, SYSCLK is restored within 60 ns. The PHY
commences SYSCLK activity by driving the SYSCLK output low for half a cycle. Thereafter, the SYSCLK
output is a 50% duty cycle square wave with a frequency of 49.152 MHz ±100 ppm (period of 20.345 ns).
Upon the first full cycle of SYSCLK, the PHY drives the CTL and D terminals low for one cycle. The LLC
is also required to drive its CTL, D, and LREQ outputs low during one of the first six cycles of SYSCLK
(shown in Figure 26 as occurring in the first SYSCLK cycle).
3. Receive indicated. Upon the eighth SYSCLK cycle following reassertion of LPS, the PHY asserts the
Receive state on the CTL lines and the data-on indication (all ones) on the D lines for one or more cycles
(because the interface is in the differentiated mode of operation, the CTL and D lines are in the
high-impedance state after the first cycle).
4. 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.
46
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SLLS424F − JUNE 2000 − REVISED MARCH 2004
PRINCIPLES OF OPERATION
ISO
(high)
7 Cycles
SYSCLK
(3)
(2)
CTL0
(4)
CTL1
D0−D7
LREQ
(1)
LPS
TCLK_ACTIVE
Figure 27. Interface Initialization, ISO High
The sequence of events for initialization of the PHY-LLC interface when the interface is in the nondifferentiated
mode of operation (ISO terminal is high) is as follows:
1. 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 Figure 27, the interface is shown in the disabled state with SYSCLK low
inactive. However, the interface initialization sequence described here is also executed if the interface is
merely reset but not yet disabled.
2. SYSCLK activated. If the interface is disabled, the PHY reactivates its SYSCLK output when it detects that
LPS has been reasserted. If the PHY has entered a low-power state, it takes between 5.3 ms to 7.3 ms for
SYSCLK to be restored; if the PHY is not in a low-power state, SYSCLK is restored within 60 ns. The
SYSCLK 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 seven cycles of SYSCLK, 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 one of the first six cycles of SYSCLK
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.
3. Receive indicated. Upon the eighth SYSCLK cycle following reassertion of LPS, the PHY asserts the
Receive state on the CTL lines and the data-on indication (all ones) on the D lines for one or more cycles.
4. 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.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
47
IMPORTANT NOTICE
Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications,
enhancements, improvements, and other changes to its products and services at any time and to discontinue
any product or service without notice. Customers should obtain the latest relevant information before placing
orders and should verify that such information is current and complete. All products are sold subject to TI’s terms
and conditions of sale supplied at the time of order acknowledgment.
TI warrants performance of its hardware products to the specifications applicable at the time of sale in
accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI
deems necessary to support this warranty. Except where mandated by government requirements, testing of all
parameters of each product is not necessarily performed.
TI assumes no liability for applications assistance or customer product design. Customers are responsible for
their products and applications using TI components. To minimize the risks associated with customer products
and applications, customers should provide adequate design and operating safeguards.
TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right,
copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process
in which TI products or services are used. Information published by TI regarding third-party products or services
does not constitute a license from TI to use such products or services or a warranty or endorsement thereof.
Use of such information may require a license from a third party under the patents or other intellectual property
of the third party, or a license from TI under the patents or other intellectual property of TI.
Reproduction of information in TI data books or data sheets is permissible only if reproduction is without
alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction
of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for
such altered documentation.
Resale of TI products or services with statements different from or beyond the parameters stated by TI for that
product or service voids all express and any implied warranties for the associated TI product or service and
is an unfair and deceptive business practice. TI is not responsible or liable for any such statements.
Following are URLs where you can obtain information on other Texas Instruments products and application
solutions:
Products
Applications
Amplifiers
amplifier.ti.com
Audio
www.ti.com/audio
Data Converters
dataconverter.ti.com
Automotive
www.ti.com/automotive
DSP
dsp.ti.com
Broadband
www.ti.com/broadband
Interface
interface.ti.com
Digital Control
www.ti.com/digitalcontrol
Logic
logic.ti.com
Military
www.ti.com/military
Power Mgmt
power.ti.com
Optical Networking
www.ti.com/opticalnetwork
Microcontrollers
microcontroller.ti.com
Security
www.ti.com/security
Telephony
www.ti.com/telephony
Video & Imaging
www.ti.com/video
Wireless
www.ti.com/wireless
Mailing Address:
Texas Instruments
Post Office Box 655303 Dallas, Texas 75265
Copyright  2004, Texas Instruments Incorporated