SONY CXD1944R

CXD1944R
PRELIMINARY
IEEE1394 3-port 200Mbps Cable Transceiver/Arbiter
Description
64 pin LQFP (plastic)
The CXD1944R is a PHY chip which suppor ts
100/200Mbps speeds and performs cable interface and
bus arbitration. It conforms to the high performance serial bus IEEE1394-1995 standard. The structure is 0.4µm
CMOS and it operates on a single 3.3V power supply.
Features
• Conforms to IEEE1394-1995
• Single 3.3V power supply
• Supports 100/200Mbps speeds
Operating Conditions
• Automatic power down for unused ports
• Supply voltage
• Power down mode to conserve energy
• Operating temperature Ta
VDD
3.0 to 4.5
V
–20 to +75
°C
• Supports short reset operation
• Supports ping for optimization of a Gap_count
Package
64-pin plastic LQFP (VQFP)
Absolute Maximum Ratings
–0.5 to +4.6
V
• Supply voltage
VDD
• Input voltage
VI
• Output voltage
VO VSS –0.5 to VDD +0.5 V
Applications
VSS –0.5 to VDD +0.5 V
• Operating temperature Ta
–20 to +70
°C
• Storage temperature
–55 to +150
°C
Tstg
When used with a LINK chip (e.g. CXD1940R), allows
configuration of a high-speed digital serial interface.
Structure
0.4µm CMOS monolithic IC
• Allowable power dissipation
PD
1000
mW
Sony reserves the right to change products and specifications without prior notice. This information does not convey any license by any implication
or otherwise under any patents or other right. Application circuits shown, if any, are typical examples illustrating the operation of the devices. Sony
cannot assume responsibility for any problems arising out of the use of these circuits.
–1–
PE96431–ST
CXD1944R
Block Diagram
CMC/LKON
PC0
PC1
PC2
TIO
TEST0
TEST1
LDSEL
CPS
LPS
XISO
SYSCLK
LREQ
CTL0
CTL1
D0
D1
D2
D3
TPA1+
TPA1–
Cable Port 1
TPB1+
TPB1–
Arbitration
and Control
State Machine
Logic
Cable Port 2
Link
Interface
I/O
TPB2+
TPB2–
TPA3+
TPA3–
Cable Port 3
TPB3+
TPB3–
Received Data
Decoder and
Retimer
XRESET
TPA2+
TPA2–
Transmit Data
Encoder
–2–
Voltage and
Current
Generator
Crystal
Oscillator PLL
System and
Transmit Clock
Generator
TB1
TB2
TB3
R1
R0
XI
XO
FLT
CXD1944R
49 AVSS
50 AVSS
51 AVDD
52 PLLVSS
53 PLLVSS
54 FLT
55 PLLVDD
56 XI
57 XO
58 DVDD
59 R0
60 R1
61 AVSS
62 XISO
63 AVSS
64 AVSS
Pin Configuration
6
43 TPB1+
PWD
7
42 TPB1–
DVSS
8
41 AVSS
SYSCLK
9
40 TPA2+
DVSS 10
39 TPA2–
CTL0 11
38 TPB2+
CTL1 12
37 TPB2–
D0 13
36 TPA3+
D1 14
35 TPA3–
D2 15
34 TPB3+
D3 16
33 TPB3–
–3–
AVSS 32
DVDD
CNA 31
44 TPA1–
PC2 30
5
PC1 29
LDSEL
PC0 28
45 TPA1+
CMC/LKON 27
4
AVSS 26
VDD-IO
AVDD 25
46 TB1
AVDD 24
3
CPS 23
LREQ
TEST0 22
47 TB2
TEST1 21
2
DVDD 20
LPS
XSLOW 19
48 TB3
TIO 18
1
CAP 17
XRESET
CXD1944R
Pin Description
Pin No.
Symbol
I/O
Description
1
XRESET
I
Reset input. Asserts at LOW. A power-on reset signal can be generated by
adding a 0.1µF capacitor.
2
LPS
I
LINK power supply status. LINK power supply is connected.
3
LREQ
I
LINK request input.
4
VDD-IO
Supply
5
LDSEL
I
6
DVDD
Supply
7
PWD
I
8
DVSS
Supply
9
SYSCLK
OUT
10
DVDD
Supply
11
CTL0
I/O
I/O of bidrectional control signals for LINK.
12
CTL1
I/O
I/O of bidrectional control signals for LINK.
13
D0
I/O
I/O of bidirectional data signals for LINK.
14
D1
I/O
I/O of bidirectional data signals for LINK.
15
D2
I/O
I/O of bidirectional data signals for LINK.
16
D3
I/O
I/O of bidirectional data signals for LINK.
17
CAP
I
18
TIO
I/O
19
XSLOW
I
20
DVDD
Supply
21
TEST1
I
Test mode control. Normally connected to ground.
22
TEST0
I
Test mode control. Normally connected to ground.
23
CPS
I(A)
24
AVDD
Supply
Analog circuit power supply.
25
AVDD
Supply
Analog circuit power supply.
26
AVSS
Supply
Analog circuit power ground.
27
CMC/LKON
I/O
28
PC0
I
Power Class input (LSB).
29
PC1
I
Power Class input.
30
PC2
I
Power Class input (MSB).
31
CNA
O
Cable Not Active output. This output is debounced.
32
AVSS
Supply
Analog circuit power ground.
33
TPB3–
I/O(A)
Port3, Cable Pair B–.
34
TPB3+
I/O(A)
Port3, Cable Pair B+.
IO power supply.
LINK delay select.
Digital circuit power supply.
Power down input.
Digital circuit ground.
System clock output; 49.152MHz clock to LINK.
Digital circuit power supply.
Connect to ground via 0.1µF capacitor when a 5V LINK is used.
Connect to VSS or VDD. If then connected to VDD, short reset mode is
selected.
When XSLOW = LOW, a device acts as a 100M PHY. Normally connected
to VDD.
Digital power supply.
Cable power status input. Normally connected to cable power.
Configuration Manager Capable input, LINK ON clock (6MHz) output.
When LPS = LOW and a LinkOn packet is received, the 6MHz clock
signal continues to be output. Connect to VDD or VSS with a 10KΩ resister.
The configuration management function is indicated when connected to
VDD.
–4–
CXD1944R
Pin No.
Symbol
I/O
Description
35
TPA3–
I/O(A)
Port3, Cable Pair A–.
36
TPA3+
I/O(A)
Port3, Cable Pair A+.
37
TPB2–
I/O(A)
Port2, Cable Pair B–.
38
TPB2+
I/O(A)
Port2, Cable Pair B+.
39
TPA2–
I/O(A)
Port2, Cable Pair A–.
40
TPA2+
I/O(A)
Port2, Cable Pair A+.
41
AVSS
Supply
Analog circuit power ground.
42
TPB1–
I/O(A)
Port1, Cable Pair B–.
43
TPB1+
I/O(A)
Port1, Cable Pair B+.
44
TPA1–
I/O(A)
Port1, Cable Pair A–.
45
TPA1+
I/O(A)
Port1, Cable Pair A+.
46
TB1
O(A)
Tp bias output. Output 1.85V (typ.), and Hi-Z during chip reset and power
down. Corresponds to one port.
47
TB2
O(A)
Tp bias output. Output 1.85V (typ.), and Hi-Z during chip reset and power
down. Corresponds to one port.
48
TB3
O(A)
Tp bias output. Output 1.85V (typ.), and Hi-Z during chip reset and power
down. Corresponds to one port.
49
AVSS
Supply
Analog circuit power ground.
50
AVSS
Supply
Analog circuit power ground.
51
AVDD
Supply
Analog circuit power supply.
52
PLLVSS
Supply
PLL circuit power ground.
53
PLLVSS
Supply
PLL circuit power ground.
54
FLT
O(A)
55
PLLVDD
Supply
56
XI
I(A)
Crystal oscillator (24.576MHz±100ppm). The optimum values for the 100kΩ
resistor and 20pF capacitor.
57
XO
O(A)
Crystal oscillator (24.576MHz±100ppm). The optimum values for the 100kΩ
resistor and 20pF capacitor.
58
DVDD
Supply
59
R0
I(A)
Reference resistance pin. Connect R1 and R0 with 6.8kΩ±5% resistor. R0
may be connected to ground.
60
R1
O(A)
Reference resistance pin. Connect R1 and R0 with 6.8kΩ±5% resistor. R0
may be connected to ground.
61
AVSS
Supply
62
XISO
I
63
AVSS
Supply
Analog circuit power ground.
64
AVSS
Supply
Analog circuit power ground.
PLL loop filter.
PLL circuit power supply.
Digital circuit power supply.
Analog circuit power ground.
XISO = LOW indicates isolation barrier which enables digital differentiator.
–5–
CXD1944R
Recommended Operating Conditions
Item
Symbol
Conditions
Supply voltage
VDD
High level input
VIH
XRESET, LPS, LREQ, CTL0
Low level input
VIL
XRESET, LPS, LREQ, CTL0
Differential input
VID-100
Cable input, 100Mbps
Differential input
VID-200
Differential input
Min.
Typ.
Max.
Unit
3.0
3.3
3.6
V
0.8VDD
V
0.2VDD
V
142
260
mV
Cable input, 200Mbps
132
260
mV
VID-ARB
Cable input, Arbitration
171
260
mV
Common input
VCM-100
TpB Cable input, 100Mbps or
speed signaling off
1.165
2.515
V
Common input
VCM-200
TpB Cable input, 200Mbps,
speed signaling on
0.935
2.515
V
Differential input jitter
JTT100
Cable input, 100Mbps
±1.08
ns
Differential input skew
SKW100
Between TpA and TpB, 100Mbps
±0.80
ns
Differential input jitter
JTT200
Cable input, 200Mbps
±0.50
ns
Differential input skew
SKW200
Between TpA and TpB, 200Mbps
±0.55
ns
Output current (1)
IOH/IOL
SYSCLK, CTL0, CTL1, D0, D1,
D2, D3, CMC/LKON
±12
IO
TB1, TB2, TB3
–1.3
mA
9.68
mA
Electrical Characteristics
Driver
Item
Symbol
Differential output voltage
Common mode current (2)
Speed signal common mode
current (2)
Conditions
Min.
Max.
Unit
265
mV
VOD
55Ω load
ICM
Driver on, speed signaling off –0.40
0.22
mA
ICM-SP
200Mbps speed signaling on
–2.53
mA
20
mV
Common mode voltage when driver is off (2) VOFF
Driver off, speed signaling off
172
Typ.
–4.84
NOTES:
1. For output current, all source current is positive (+) and sink current is negative (–).
2. Common mode current is the average value of the currents output from TPB+ and TPB–. The same applies to TPA+ and TPA–.
–6–
CXD1944R
Receiver
Item
Symbol
Conditions
Min.
Common mode input current
IIC
Driver off
–20
Differential input impedance
ZID
Driver off
15
Differential input threshold
VTH
–30
Arbitration differential input threshold
VTH+
“1” input
168
VTHZ
“Z” input
–89
VTH–
“0” input
Speed signal detection threshold
VTH-SP
TB-TPA common mode
potential
Cable bias detection threshold
VTH-CB
TPB common mode
input
–7–
Typ.
Max.
Unit
20
µA
kΩ
24
pF
30
mV
mV
89
mV
–168
mV
49
131
mV
0.6
1.0
V
CXD1944R
Device
Item
Supply current
I/O supply voltage
Symbol
Max.
Unit
VDD = 3.6V
100
mA
VDD = 3.6V when cable is not connected
50
mA
IDD-PD
VDD = 3.6V, Power down mode
10
mA
VDD-IO
When a 5V LINK is used
4.5
5.5
V
When a 3V LINK is used
3.0
3.6
V
IDD
Condition
High level output
VOH
SYSCLK, CTL0, CTL1, D0, D1, D2, D3,
CMC/LKON, IOH = 12mA, VDD = min.
Low level output
VOL
SYSCLK, CTL0, CTL1, D0, D1, D2, D3,
CMC/LKON, IOL = 12mA, VDD = max.
Min.
Typ.
VDD–0.4
V
0.4
0.6VDD
V
High level input threshold VTH+
XRESET, LPS, LREQ, PWD, CTL0, CTL1,
D0, D1, D2, D3
V
Low level input threshold
VTH–
XRESET, LPS, LREQ, PWD, CTL0, CTL1,
D0, D1, D2, D3
0.4VDD
V
Input leak current
IIL
XRESET, LPS, LREQ, PWD, CTL0, CTL1,
D0, D1, D2, D3, VI = 0V or VDD
±10
µA
Output leak current
when output is off
IOZ
SYSCLK, CTL0, CTL1, D0, D1, D2, D3,
CMC/LKON
±40
µA
Power up reset time
TPWR
CPS input threshold
VTH-CPS
200kΩ resistor
5.5
7.5
V
CPS input current
ICPS
CPS pin at 1.85V
20
30
µA
TB output voltage
VO
1.665
2.015
V
R1 pin output voltage
VR1
0.635
0.761
V
2
IR1 = 100µA
–8–
ms
CXD1944R
I/O Pin Capacitance
Item
Symbol
Conditions
Min.
Typ.
Max.
Unit
Input pin capacitance
CIN
XRESET, LPS, LREQ, PC0, PC1, PC2, CPS
11
pF
Output pin capacitance
COUT
SYSCLK
11
pF
CTL0, CTL1, D0, D1, D2, D3, CMC/LKON
11
pF
Max.
Unit
Input/Output capacitance CI/O
AC Characteristics
Item
Symbol
Conditions
Min.
Typ.
Output jitter
JTT
TPA, TPB
±0.25
ns
Output skew
SKW
Between TPA and TPB
±0.15
ns
Output rise time
Tr
TPA, TPB, 10 to 90%, RL = 55Ω, CL = 10pF
2.2
ns
Output fall time
Tf
TPA, TPB, 90 to 10%, RL = 55Ω, CL = 10pF
2.2
ns
Setup time
Tsu
LREQ, CTL0, CTL1, D0, D1, D2, D3 relative
to SYSCLK, LDSEL = HIGH
5
ns
LREQ, CTL0, CTL1, D0, D1, D2, D3
relative to SYSCLK, LDSEL = LOW
0
ns
LREQ, CTL0, CTL1, D0, D1, D2, D3
relative to SYSCLK, LDSEL = HIGH
2
ns
LREQ, CTL0, CTL1, D0, D1, D2, D3
relative to SYSCLK, LDSEL = LOW
7
ns
Hold time
Thd
Output delay time
Output disable
time(1)
Td
CTL0, CTL1, D0, D1, D2, D3 from SYSCLK
2.5
11
ns
Thz
CTL0, CTL1, D0, D1, D2, D3 from SYSCLK
1.5
0.0
ns
NOTE:
1. When control of CTL0, CTL1 and D0 to 3 passes from PHY to LINK. Refer to the section on Transmit.
–9–
CXD1944R
Switching Waveforms
SysCLK
tsu
thd
LReq,
Ctl,
Data
LReq, Ctl, Data setup time and hold time
SysCLK
td
Ctl, Data
SysCLK
tHZ
Hi-Z
Ctl, Data
Ctl, Data Output Delay
Internal Register
MSB
Address
LSB
0
1
2
0000
0001
3
4
5
Physical-ID
RHB
IBR
6
7
R
CPS
GC
0010
SPD = 01
0011
ASTAT1
BSTAT1
Ch1
Con1
0
P1Fast
0100
ASTAT2
BSTAT2
Ch2
Con2
0
P2Fast
0101
ASTAT3
BSTAT3
Ch3
Con3
0
P3Fast
0
0
0
Slow Bit
ArbRstReq
0110
LoopInt
0111
0
CPStatInt
NP = 00011
CPStat
IDidIt
Reserved
Chip Rev
1000
1001
Illegal LReq
Reserved
0
0
0
0
0
1010
Ping Timer [15 : 8]
1011
Ping Timer [7 : 0]
–10–
Slow Pin
CXD1944R
Name
Size
Type
Description
Physical-ID
6
R
The address number of this node. Determined during Self-ID.
R
1
R
Indicates that this node is the root.
CPS
1
R
Cable power status.
RHB
1
R/W
Root Holding Bit. Attempts to become the root during next bus reset if set to “1”.
IBR
1
R/W
Initiate Bus Reset. Generates bus reset when possible after being set to “1”.
Cleared after bus reset.
GC
6
R/W
Gap Count. Used to optimize gap time according to bus scale.
SPD
2
R
Indicates this node’s highest speed; 200Mbps when “01”, 100Mbps when “00”.
NP
4
R
Indicates the number of ports on this node.
ASTAT(n)
2
R
Indicates port n TPA status.
11 = Z, 01 = 1, 10 = 0, 00 = invalid
BSTAT(n)
2
R
Indicates port n TPB status.
11 = Z, 01 = 1, 10 = 0, 00 = invalid
Ch(n)
1
R
When the value is “1”, indicates that port n is the Child. “0” indicates Parent.
Con(n)
1
R
When the value is “1”, indicates that the active cable is connected to port n.
P(n) Fast
1
R
When the value is “1”, indicates that port n supports 200Mbps.
LoopInt
1
R/W
This is set to “1” when Tree-ID is not completed in time, which means that the
bus may be forming a loop.
CPStatInt
1
R/W
Indicates a drop in cable power line voltage.
CPStat
1
R
Same as CPS.
IDidIt
1
R
Indicates that this node generates the last bus reset. More than one node
may set this value.
IllegalReq
1
R
Indicates an illegal LReq is detected.
ChipRev
4
R
Indicates the chip revision number.
Slow Pin
1
R
Indicates XSLOW pin is set to LOW.
Slow Bit
1
R/W
When set to “1”, the node acts as a 100Mbps PHY. Default is “0”.
ArbRstReq
1
R/W
Initiate the arbitrated bus reset. Cleared after bus reset.
Ping Timer
16
R
50MHz Ping Timer count. A count starts when a configuration packet is transmitted and stops when the first packet is received. The value may not be cleared
until the next configuration packet is sent.
–11–
CXD1944R
External Components and Pin Connection
220pF
2.4kΩ
20pF
20pF
20pF
100kΩ
6.6kΩ
AVSS 49
AVSS 50
AVDD 51
AVSS 52
AVSS 53
FLT 54
VDD
AVDD 55
XI 56
XO 57
DVDD 58
R0 59
R1 60
AVSS 61
DVSS 63
DVSS 64
VDD
TPB3 48
2 LPS
TPB2 47
3 LREQ
TPB1 46
4 VDD-IO
TPB1+ 45
5 LDSEL
TPA1– 44
VDD
6 DVDD
TPB1+ 43
Power
Down
7 PWD
TPB1– 42
8 DVSS
AVSS 41
TPB2– 37
13 D0
TPA3+ 36
14 D1
TPA3– 35
0.1µF
200kΩ
VDO
/SLOW
VDD
Cable Power
32 AVSS
Power Class
Programming
10kΩ
Link On Configuration
–12–
31 CNA
30 PC2
29 PC!
TPB3+ 34
28 PC0
16 D3
23 CPS
15 D2
27 CMC/LKON
TPB2+ 38
12 CTL1
26 AVSS
11 CTL0
25 AVDD
TPA2– 39
24 AVDD
10 DVSS
22 TEST0
TPA2+ 40
21 TEST1
9 SYSCLK
20 DVDD
LDSEL
19 XSLOW
10kΩ
18 TIO
LINK VDD
LINK Controller
Interface
VDD
1 XRESET
17 CAP
0.1µF
XISO 62
/ISO
VDD
CNA Out
TPB3– 33
Tp Bias
Tp Cables
Tp Cables
CXD1944R
Twisted Pair Cable Connection
CPS
Power pair
200kΩ
TPAn+
Cable pair A
TPAn–
55Ω
Cable Port (n)
55Ω
TPBn+
Cable pair B
TPBn–
TPBSn
55Ω
55Ω
0.33µF
250pF
Description of Operation
The CXD1994R is used with LINK controllers such as
the CXD1940R to configure a high speed serial bus. It
has three ports which support speeds of 100M/200Mbps.
There are four basic operations which may occur in
the interface: request, status, transmit, and receive. All
bit request are initiated by the PHY. The LINK uses the
5kΩ
request operation to read or write an internal PHY register or to ask the PHY to initiate a transmit action. The
PHY initiates a receive action whenever a packet is
received from the serial bus.
The serial bus is always 2 bits wide, independent of
speed.
The encoding of these pins is as follows:
CTL [0 : 1] When PHY is Driving
CTL [0: 1]
Name
Meaning
00
Idle
No activity.
01
Status
The PHY is sending status information to the LINK.
10
Receive
An incoming packet is being transferred from the PHY to the LINK.
11
Transmit
The LINK is granted the bus to send a packet.
CTL [0 : 1] When the LINK is Driving (upon a grant from PHY)
CTL [0: 1]
Name
Meaning
00
Idle
Transmission complete, release bus.
01
Hold
The LINK is holding the bus while preparing data or indicating it wishes to
reacquire the bus without arbitration to send another packet.
10
Transmit
The LINK is sending a packet to the PHY.
11
Reserved
Unused.
–13–
CXD1944R
LINK Request
To request the bus or access a PHY register, the LINK
sends a short stream to the PHY on the LREQ pin. The
information sent includes the type of request to which the
packet is to be sent, or a read or write command. The
transfer can be either 7 bits, 9 bits or 17 bits, depending
on whether it is a bus request, a read access, or a write
access, repectively. A stop bit of 0 is required after each
request transfer before another transfer may begin.
Bus Request Format
Bit(s)
Name
Description
0
Start Bit
Indicates start of transfer. Always 1.
1 to 3
Request Type
Indicates which type of bus request is being performed. See the table below
for the encoding of this field.
4 to 5
Request Speed
The speed at which the PHY will be sending the packet for this request. This
field has the same encoding as the speed code from the first symbol of the
receive packet. See the following table for the encoding of this field.
6
Stop Bit
Indicates end of transfer. Always 0.
If the transfer is a read request, it is 9 bits long and
has the following format:
Read Request Format
Bit(s)
Name
Description
0
Start Bit
Indicates start of transfer. Always 1.
1 to 3
Request Type
Indicates that this is a register read. See the following table for the encoding of
this field.
4 to 7
Address
The internal PHY register address to be read.
8
Stop Bit
Indicates end of transfer. Always 0.
If the transfer is a write request, it is 17 bits long and
has the following format:
Write Request Format
Bit(s)
Name
Description
0
Start Bit
Indicates start of transfer. Always 1.
1 to 3
Request Type
Indicates that this is a register read. See the following table for the encoding
of this field.
4 to 7
Address
The internal PHY register address to be written.
8 to 15
Data
The data to be written to the specified address.
16
Stop Bit
Indicates end of transfer. Always 0.
–14–
CXD1944R
The request type field is encoded as follows:
Request Type Field
LREQ [1 : 3]
Name
Meaning
000
ImmReq
Take control of the bus immediately upon detecting idle; do not arbitrate. Used
for acknowledge transfers.
001
IsoReq
Arbitrate for the bus; no gaps. Used for isochronous transfers.
010
PriReq
Arbitrate after a subaction gap; ignore fair protocol. Used for cycle start
packet.
011
FairReq
Arbitrate after a subaction gap, following fair prototcol. Used for fair transfers.
100
RdReq
Return specified register contents through status transfer.
101
WrReg
Write to specified register.
110 to 111
Reserved
Ignored.
The request speed field is encoded as follows:
Request Speed Field
LREQ [4 : 5]
Data Rate
00
100Mbps
01
200Mbps
10
400Mbps
11
>400Mbps
NOTE:
The CXD1944R does not support 400Mbps and over.
–15–
CXD1944R
LREQ Timing
LR0
LR1
LR2
LR3
FairReq and PrioReq:
To request the bus for fair or priority access, the LINK
sends the request at least one clock after the interface
becomes idle. The LINK interprets the receive state on
the CTL pins as a lost request. If the LINK sees the
receive state anytime during or after it sends the request
transfer, it assumes the request is lost and reissues the
request on the next idle. The PHY will ignore a fair or priority request if it asserts the receive state anytime during
the request transfer. Note that the minimum length of a
packet is two clock cycles in the case of 400Mbps
acknowledge packet. The minimum request packet is 8
clock cycles. It is important that the LINK and PHY agree
to interpret a lost request the same way.
The cycle master node uses a priority request
(PriReq) to send the cycle start message. To request the
bus to send isochronous data, the LINK can issue the
request at any time after receiving the cycle start. The
PHY will clear an isochronous request only when the bus
has been won.
ImmReq:
To send an acknowledge, the LINK must issue an
ImmReq request during the reception of the packet
addressed to it. This is required because the delay from
end of packet to acknowledge request adds directly to
the minimum delay every PHY must wait after every
packet to allow an acknowledge to occur. After the packet ends, the PHY immediately takes control of the bus
and grants the bus to the LINK. If the header CRC of the
packet turns out to be bad, the LINK releases the bus
immediately. The LINK cannot use this grant to send
another type of packet. To ensure this, the LINK must
wait 160ns after the end of the received packet to allow
the PHY to grant it the bus for the acknowledge, then
release the bus and proceed with another request.
Though highly unlikely, it is conceivable that two different nodes can perceive (one correctly, one mistakenly) that an incoming packet is intended for them and both
issue an acknowledge request before checking the CRC.
Both nodes’ PHYs would grab control of the bus immediately after the packet is complete. This condition will
LR (n – 2)
LR (n – 1)
cause a temporary, localized collision of the data-on line
states somewhere between two PHYs intending to
acknowledge. All other PHYs on the bus would see the
data-on state. This collision would appear as a “zz” line
state, and would not be interpreted as a bus reset. The
mistaken node would drops its request as soon as it has
checked the CRC and spurious “zz” line states would go
away. The only side effect of such a collision would be
the loss of the intended acknowledge packet, which
would be handled by the higher-layer protocol.
IsoReq:
To send an isochronous packet, the LINK is recommended to issue an IsoReq request during the reception
or transmission (if root) of a cycle start packet or another
isochronous packet. This is required to keep an isochronous gap short. Any IsoReq will be cleared when a packet is transmitted or a certain time (80ns) is passed in idle
after the bus seized. (This timeout is not a part of the
IEEE1394-1995 standard.) When the LINK issues an
IsoReq before CRC check of a cycle start packet and the
CRC is found wrong after the IsoReq, the LINK may
release the bus without sending a packet when the bus is
granted.
Read/Write Request:
For write requests, the PHY takes the value in the data
field of the transfer and loads it into the addressed register as soon as the transfer is complete. For read
requests, the PHY returns the contents of the addressed
register at the next opportunity through a status transfer.
The LINK is allowed to perform a read or write operation
at any time. If the status transfer is interrupted by an
incoming packet, the PHY continues to attempt the transfer of the requested register until it is successful.
Once the LINK issues a request for access to the bus
(immediate, iso, fair, or priority) it cannot issue another
request until the PHY indicates “lost” (incoming packet)
or “won” (transmit). The PHY ignores new requests while
a previous request is pending.
–16–
CXD1944R
Status Transfer
When the PHY has status information to transfer to
the LINK, it will initiate a status transfer. The PHY will wait
until the interface is idle to perform the transfer. The PHY
initiates the transfer by asserting status (01b) on the CTL
pins, along with the first two bits of status information on
D [0 : 1]. The PHY maintains CTL = status for the dura-
tion of the status transfer. The PHY may prematurely end
a status transfer by asserting something other than status on the CTL pins. This should be done in the event
that a packet arrives before the status transfer completes. There must be at least one cycle in between consecutive status transfers.
Status Transfer Timing
PHY
CTL [0:1]
00
01
01
01
00
00
PHY
D [0:1]
00
s[0:1]
s[2:3]
s[14:15]
00
00
–17–
CXD1944R
during a single cycle. The only requirement when sending multiple packets during a single bus ownership is that
all must be transmitted at the same speed, since the
speed of the packet transmission is set before the first
packet.
As noted above, when the LINK has finished sending
the last packet for the current bus ownership, it releases
the bus by asserting idle on the CTL pins for two SCLK
cycles. The PHY begins asserting idle on the CTL pins
one clock after sampling idle from the link. Note that
whenever the D and CTL lines change “ownership”
between the PHY and the LINK, there is an extra clock
period allowed so that both sides of the interface can
operate on registered versions of the interface signals,
rather than having to respond to a CTL state on the next
cycle.
Note that it is not required that the LINK enter the hold
state before sending the first packet if implementation
permits the LINK to be ready to transmit as soon as bus
ownership is granted. The timing for a single packet
transmit operation is shown below. In the diagram, D0
through Dn are the data symbols of the packet; zz represents high impedance state.
Transmit:
When the LINK requests access to the serial bus
through the LREQ pin, the PHY arbitrates for access to
the serial bus. If the PHY wins the arbitration, it grants the
bus to the LINK by asserting transmit on the CTL pin for
one SCLK cycle, followed by idle for one cycle. After
sampling the transmit state from the PHY, the LINK takes
over control of the interface by asserting either hold or
transmit on the CTL pins. The LINK asserts hold to keep
ownership of the bus while preparing data. The PHY
asserts the data-on state on the serial bus during this
time. When it is ready to begin transmitting a packet, the
LINK asserts transmit on the CTL pins along with the first
bits of the packet. After sending the last bits of the packet, the link asserts either idle or hold on the on the CTL
pins for one cycle, and then idle for one additional cycle
before tristating those pins.
The hold state here indicates to the PHY that the LINK
needs to send another packet without releasing the bus.
The PHY responds to this hold state by waiting the
required minimum time and then asserting transmit as
before. This function would be used after sending an
acknowledge if the LINK intends to send a unified
response, or to send consecutive isochronous packets
Transmit Timing
Single Packet
PHY
CTL [0:1]
00
11
00
zz
zz
zz
zz
zz
zz
zz
zz
00
PHY
D [0:1]
00
00
00
zz
zz
zz
zz
zz
zz
zz
zz
00
LINK
CTL [0:1]
zz
zz
zz
01
01
10
10
10
10
00
00
zz
LINK
D [0:1]
zz
zz
zz
00
00
D0
D1
D2
Dn
00
00
zz
Continued Packet
PHY
CTL [0:1]
zz
zz
zz
zz
00
00
11
00
zz
zz
zz
zz
PHY
D [0:1]
zz
zz
zz
zz
00
00
00
00
zz
zz
zz
zz
LINK
CTL [0:1]
10
10
01
00
zz
zz
zz
zz
01
01
10
10
Dn–1
Dn
00
00
zz
zz
zz
zz
00
00
D0
D1
LINK
D [0:1]
NOTES:
zz = Hi-Z
D0 to Dn = Packet data
This figure is for 100Mbps. For 200Mbps, D [0:3] is used.
–18–
CXD1944R
is a PHY-LINK protocol and is not included in the calculation of the CRC or other data protection mechanisms.
It is possible that a PHY can see date-on appear and
then disappear on the serial bus without seeing a packet.
This is the case when a packet of a higher speed than the
PHY can receive is being transmitted. In this case, the
PHY will end the packet by asserting idle when the dataon state goes away.
If the PHY is capable of a higher data rate than the
LINK, the LINK detects the speed code as such and
ignores the packet until it sees the idle state again.
Receive:
Whenever the PHY sees the “data-on” state on the
serial bus, it initiates a receive operation by asserting
receive on the CTL pins and “1” on each of the D pins.
The PHY indicates the start of a packet by placing the
speed code (encoding shown below) on the D pins, followed by the contents of the packet, holding the CTL pins
in receive until the last symbol of the packet has been
transferred. The PHY indicates the end of the packet by
asserting idle on the CTL pins. Note that the speed code
Receive Timing
PHY
CTL [0:1]
PHY
D [0:3]
(hex)
00
10
10
10
10
10
10
00
00
0
F
F
SPD
D0
D1
Dn
0
0
NOTES:
SPD = speed code
D0 to Dn = data symbols of the packet; for 100Mbps, packet data is output to D [0 : 1] only.
The speed code for the receive operation is defined
as follows:
Receive Speed Code
D[0 : 3]
Data Rate
00xx
100Mbps
0100
200Mbps
NOTE:
The “xx” means transmitted as 00, ignored on receive.
–19–
CXD1944R
Power Class Programming
Power use or power supply from the cable requires
certain settings. PC [2 : 0] is used for this setting.
The power classes are defined as follows:
PC [2 : 0]
Definition
000
The node does not consume cable power. Also, power does not repeat.
001
The node operates on its own power, and a minimum of 15W is supplied to the cable.
010
The node operates on its own power, and a minimum of 30W is supplied to the cable.
011
The node operates on its own power and a minimum of 45W is supplied to the cable.
100
The node may use cable power. Maximum required power is 1W.
101
The node may use cable power. Maximum required power is 1W. A further 2W are required to
operate LINK and upper layer.
110
The node may use cable power. Maximum required power is 1W. A further 5W are required to
operate LINK and upper layer.
111
The node may use cable power. Maximum required power is 1W. A further 9W are required to
operate LINK and upper layer.
Additional Features
Short Bus Reset:
The short bus reset or arbitrated bus reset were proposed in the 1394 Trade Association by Apple Computer.
The standardization, however, has not been done yet.
The CXD1944R supports a short bus reset mode whose
reset pulse width is 1.4µs instead of the normal bus reset
pulse width of 166µs. This mode can be selected by connecting the TIO pin to VDD. When the node needs to send
a reset pulse, it will first arbitrate the bus according to the
fair protocol as a FairReq. If it gets the bus grant, it will
send a short bus reset pulse instead of a packet. This is
called “arbitrated bus reset”, which ensures all nodes can
detect the short bus reset pulse. Since it follows Fair protocol, it won’t disturb the isochronous cycle. This arbitrated bus reset can only work after the bus is initialized.
Before the bus initialization, the node will send a short
bus reset pulse immediately. In both cases, if a short bus
reset fails, the node will send a normal long bus reset, so
that the short bus reset mode can be used with an older
PHY which does not support a short bus reset mode.
If the IBR bit of the internal PHY register is set to 1, the
device will send a long reset pulse. To request a short
arbitrated bus reset, write 1 to the ArbRsrReq bit in the
reset mode.
Slow Mode:
The CXD1944R supports 200Mbps. In some cable
environments, however, 200Mbps may be difficult to
operate; thus we have added the Slow Mode operation.
By connecting XSLOW pin to ground, or writing a “1” to
the Slow Bit of the internal PHY register, the device will
act as a 100Mbps PHY. D[2:3] is still active in the slow
mode.
Ping and Ping Timer:
Ping is used to measure a node-node packet delay. If
the node received an R=0 and T=0 configuration packet,
it will send a Self-ID packet immediately as an acknowledge. Since a LINK is not involved in this Self-ID transmission, and it is very quick, a sender can know the exact
packet delay between the node and the remote node.
LINK can read a Ping timer count after a Self-ID acknowledge. The Ping timer will be cleared and starts a count
only when a configuration packet is sent from the node.
The counter runs at 50MHz clock cycle. This feature is
thought useful to optimize a gap count of the bus.
–20–
CXD1944R
Package Outline
Unit: mm
64 pin LQFP (Plastic)
12.0 ±0.2
*
10.0 ±0.1
0.127 +0.05
–0.02
48
0.1
33
32
64
17
0.5 ±0.2 (11.0)
49
(0.22)
1
+0.08
0.5 ±0.08
16
0.18 –0.03
+0.2
1.5 –0.1
0.5 ±0.2
0.1 ±0.1
0°-10°
NOTE: Dimension “*” does not include mold protrusion.
Package Structure
SONY CODE
EIAJ CODE
JEDEC CODE
LQFP-64P-L01
*QFP064-P-1010-A
—
PACKAGE MATERIAL
EPOXY/PHENOL RESIN
LEAD TREATMENT
SOLDER PLATING
LEAD MATERIAL
42 ALLOY
PACKAGE WEIGHT
0.3g
–21–