ETC2 NET2272 Usb 2.0 peripheral controller Datasheet

NetChip
Technology, Inc.
335 Pioneer Way
Mt View, California 94041
(650) 526-1490 Fax (650) 526-1494
e-mail: [email protected]
Internet: www.netchip.com
NET2272 USB 2.0 Peripheral Controller
Patent Pending
For Revision 1A
Doc #: 605-0213-0110
Revision: 1.2
Date: October 15, 2003
Specification
NET2272 USB Peripheral Controller
This document contains material that is confidential to NetChip. Reproduction without the express written consent
of NetChip is prohibited. All reasonable attempts were made to ensure the contents of this document are accurate,
however no liability, expressed or implied is guaranteed. NetChip reserves the right to modify this document,
without notification, at any time.
Revision History
Revision
1.0
1.1
1.2
Issue Date
May 5, 2003
October 7, 2003
October 15, 2003
Comments
Revision 1 silicon initial release
Revision 1.1 silicon release
Power consumption update
______________________________________________________________________________
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
2
Specification
NET2272 USB Peripheral Controller
NET2272 USB Peripheral Controller
1
INTRODUCTION .................................................................................................................................8
1.1
1.2
1.3
1.4
1.5
1.5.1
1.5.2
FEATURES .....................................................................................................................................8
OVERVIEW ....................................................................................................................................8
NET2272 BLOCK DIAGRAM .......................................................................................................10
NET2272 TYPICAL SYSTEM BLOCK DIAGRAMS .........................................................................10
EXAMPLE CONNECTIONS TO NET2272........................................................................................12
Example Part Numbers..........................................................................................................13
General PCB Layout Guidelines ...........................................................................................13
1.5.2.1
1.5.2.2
1.5.2.3
1.5.2.4
1.5.2.5
1.6
2
TERMINOLOGY ............................................................................................................................14
PIN DESCRIPTION............................................................................................................................15
2.1
2.2
2.3
2.4
2.5
3
DIGITAL POWER & GROUND (10 PINS)........................................................................................15
USB TRANSCEIVER (15 PINS)......................................................................................................16
CLOCKS, RESET, MISC. (8 PINS)..................................................................................................17
LOCAL BUS PIN DESCRIPTIONS (31 PINS) ....................................................................................18
PHYSICAL PIN ASSIGNMENT ........................................................................................................19
RESET AND INITIALIZATION.......................................................................................................20
3.1
3.2
3.3
3.4
4
USB Differential Signals..................................................................................................................13
Analog VDD (power).......................................................................................................................13
Analog VSS (ground).......................................................................................................................14
Decoupling Capacitors .....................................................................................................................14
EMI Noise Suppression....................................................................................................................14
OVERVIEW ..................................................................................................................................20
RESET# PIN ...............................................................................................................................20
ROOT PORT RESET ......................................................................................................................20
RESET SUMMARY ........................................................................................................................20
LOCAL BUS INTERFACE................................................................................................................21
4.1
4.2
4.2.1
4.2.2
4.2.3
4.3
4.4
4.5
4.5.1
4.5.2
4.5.3
4.5.4
4.5.5
INTRODUCTION ............................................................................................................................21
REGISTER ADDRESSING MODES ..................................................................................................21
Direct Address Mode .............................................................................................................21
Indirect Address Mode...........................................................................................................21
Multiplexed Address Mode ....................................................................................................21
CONTROL SIGNAL DEFINITIONS ..................................................................................................21
BUS WIDTH / BYTE ALIGNMENT .................................................................................................21
I/O TRANSACTIONS .....................................................................................................................22
Non-Multiplexed I/O Read.....................................................................................................22
Multiplexed I/O Read.............................................................................................................22
Non-Multiplexed I/O Write ....................................................................................................23
Multiplexed I/O Write ............................................................................................................23
I/O Performance ....................................................................................................................24
4.5.5.1
4.5.5.2
4.5.5.3
4.5.5.4
Non-Multiplexed Read Transaction .................................................................................................24
Multiplexed Read Transaction .........................................................................................................24
Non-Multiplexed Write Transaction ................................................................................................24
Multiplexed Write Transaction ........................................................................................................24
4.6
DMA TRANSACTIONS .................................................................................................................25
4.6.1
DMA Read .............................................................................................................................25
4.6.1.1
4.6.1.2
4.6.1.3
4.6.2
4.6.2.1
Slow DMA Read Timing .................................................................................................................26
Fast DMA Read Timing...................................................................................................................26
Burst DMA Read Timing.................................................................................................................26
DMA Write.............................................................................................................................27
Slow DMA Write Timing ................................................................................................................28
______________________________________________________________________________
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
3
Specification
4.6.2.2
4.6.2.3
4.6.3
4.6.4
4.6.5
Fast DMA Write Timing ..................................................................................................................28
Burst DMA Write Timing ................................................................................................................28
DMA Split Bus Mode .............................................................................................................29
Terminating DMA Transfers..................................................................................................29
DMA Performance.................................................................................................................30
4.6.5.1
4.6.5.2
4.6.5.3
4.6.5.4
4.6.5.5
4.6.5.6
5
NET2272 USB Peripheral Controller
DMA Read; Slow Mode...................................................................................................................30
DMA Read; Fast Mode ....................................................................................................................30
DMA Read; Burst Mode ..................................................................................................................30
DMA Write; Slow Mode..................................................................................................................30
DMA Write; Fast Mode ...................................................................................................................30
DMA Write; Burst Mode .................................................................................................................31
USB FUNCTIONAL DESCRIPTION ...............................................................................................32
5.1
5.2
5.2.1
5.2.2
5.2.3
5.2.4
5.3
5.3.1
5.3.2
5.4
5.5
5.6
5.6.1
USB INTERFACE .........................................................................................................................32
USB PROTOCOL ..........................................................................................................................32
Tokens....................................................................................................................................32
Packets...................................................................................................................................32
Transaction ............................................................................................................................33
Transfer .................................................................................................................................33
AUTOMATIC RETRIES ..................................................................................................................33
Out Transactions ...................................................................................................................33
In Transactions ......................................................................................................................33
PING FLOW CONTROL..................................................................................................................33
PACKET SIZES .............................................................................................................................33
USB ENDPOINTS .........................................................................................................................34
Control Endpoint - Endpoint 0 ..............................................................................................34
5.6.1.1
5.6.2
Control Write Transfer .....................................................................................................................34
Control Write Transfer Details..............................................................................................35
5.6.2.1
5.6.2.2
5.6.3
Control Read Transfer......................................................................................................................36
Control Read Transfer Details..........................................................................................................36
Isochronous Endpoints ..........................................................................................................37
5.6.3.1
5.6.3.2
5.6.3.3
5.6.3.4
5.6.4
Isochronous Out Transactions ..........................................................................................................38
High Bandwidth Isochronous OUT Transactions.............................................................................38
Isochronous In Transactions.............................................................................................................39
High Bandwidth Isochronous IN Transactions.................................................................................39
Bulk Endpoints.......................................................................................................................40
5.6.4.1
5.6.4.2
5.6.5
Bulk Out Transactions......................................................................................................................40
Bulk In Endpoints ............................................................................................................................41
Interrupt Endpoints................................................................................................................42
5.6.5.1
5.6.5.2
5.6.5.3
Interrupt Out Transactions ...............................................................................................................42
Interrupt In Endpoints ......................................................................................................................42
High Bandwidth INTERRUPT Endpoints .......................................................................................42
5.7
NETCHIP VIRTUAL ENDPOINTS ...................................................................................................43
5.7.1
Overview:...............................................................................................................................43
5.7.2
Endpoint Virtualization..........................................................................................................43
5.7.3
Efficiency Considerations:.....................................................................................................44
5.7.4
Deadlock Considerations: .....................................................................................................45
5.7.5
Buffer Control........................................................................................................................45
5.7.6
Summary ................................................................................................................................45
5.8
PACKET BUFFERS ........................................................................................................................46
5.8.1
IN Endpoint Buffers ...............................................................................................................46
5.8.1.1
16-bit Post-Validation ......................................................................................................................47
5.8.2
OUT Endpoint Buffers ...........................................................................................................47
5.9
USB TEST MODES ......................................................................................................................48
6
INTERRUPT AND STATUS REGISTER OPERATION ...............................................................49
6.1
INTERRUPT STATUS REGISTERS (IRQSTAT0, IRQSTAT1)........................................................49
______________________________________________________________________________
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
4
Specification
6.2
6.3
7
NET2272 USB Peripheral Controller
ENDPOINT RESPONSE REGISTERS (EPRSP_CLR, EPRSP_SET).................................................49
ENDPOINT STATUS REGISTER (EP_STAT0, EP_STAT1) ...........................................................49
POWER MANAGEMENT .................................................................................................................50
7.1
SUSPEND MODE...........................................................................................................................50
7.1.1
The Suspend Sequence ...........................................................................................................50
7.1.2
Host-Initiated Wake-Up.........................................................................................................51
7.1.3
Device-Remote Wake-Up.......................................................................................................51
7.1.4
Resume Interrupt ...................................................................................................................51
7.2
NET2272 POWER CONFIGURATION ............................................................................................51
7.2.1
Self-Powered Device..............................................................................................................51
7.2.2
Low-Power Modes .................................................................................................................51
7.2.2.1
7.2.2.2
8
USB Suspend (Unplugged from USB).............................................................................................51
Power-On Standby ...........................................................................................................................52
CONFIGURATION REGISTERS.....................................................................................................53
8.1
REGISTER DESCRIPTION ..............................................................................................................53
8.2
REGISTER SUMMARY...................................................................................................................53
8.2.1
Main Control Registers..........................................................................................................53
8.2.2
USB Control Registers...........................................................................................................54
8.2.3
Endpoint Registers.................................................................................................................54
8.3
NUMERIC REGISTER LISTING.......................................................................................................55
8.4
MAIN CONTROL REGISTERS ........................................................................................................56
8.4.1
(Address 00h; REGADDRPTR) Indirect Register Address Pointer.......................................56
8.4.2
(Address 01h; REGDATA) Indirect Register Data ................................................................56
8.4.3
(Address 02h; IRQSTAT0) Interrupt Status Register (low byte)............................................56
8.4.4
(Address 03h; IRQSTAT1) Interrupt Status Register (high byte)...........................................57
8.4.5
(Address 04h; PAGESEL) Endpoint Page Select Register ....................................................57
8.4.6
(Address 1Ch; DMAREQ) DMA Request Control Register...................................................58
8.4.7
(Address 1Dh; SCRATCH) Scratchpad Register ...................................................................58
8.4.8
(Address 20h; IRQENB0) Interrupt Enable Register (low byte)............................................59
8.4.9
(Address 21h; IRQENB1) Interrupt Enable Register (high byte) ..........................................59
8.4.10 (Address 22h; LOCCTL) Local Bus Control Register ...........................................................60
8.4.11 (Address 23h; CHIPREV_LEGACY) Legacy Silicon Revision Register................................60
8.4.12 (Address 24h; LOCCTL1) Local Bus Control Register 1 ......................................................61
8.4.13 (Address 25h; CHIPREV_2272) Net2272 Silicon Revision Register.....................................61
8.5
USB CONTROL REGISTERS .........................................................................................................62
8.5.1
(Address 18h; USBCTL0) USB Control Register (low byte) .................................................62
8.5.2
(Address 19h; USBCTL1) USB Control Register (high byte) ................................................62
8.5.3
(Address 1Ah; FRAME0) Frame Counter (low byte) ............................................................62
8.5.4
(Address 1Bh; FRAME1) Frame Counter (high byte) ...........................................................62
8.5.5
(Address 30h; OURADDR) Our Current USB Address.........................................................63
8.5.6
(Address 31h; USBDIAG) USB Diagnostic Register.............................................................63
8.5.7
(Address 32h; USBTEST) USB Test Modes...........................................................................64
8.5.8
(Address 33h; XCVRDIAG) Transceiver Diagnostic Register ..............................................64
8.5.9
(Address 34h; VIRTOUT0) Virtual OUT 0 ............................................................................64
8.5.10 (Address 35h; VIRTOUT1) Virtual OUT 1 ............................................................................65
8.5.11 (Address 36h; VIRTIN0) Virtual IN 0 ....................................................................................65
8.5.12 (Address 37h; VIRTIN1) Virtual IN 1 ....................................................................................65
8.5.13 (Address 40h; SETUP0) Setup Byte 0....................................................................................65
8.5.14 (Address 41h; SETUP1) Setup Byte 1....................................................................................66
8.5.15 (Address 42h; SETUP2) Setup Byte 2....................................................................................66
8.5.16 (Address 43h; SETUP3) Setup Byte 3....................................................................................66
8.5.17 (Address 44h; SETUP4) Setup Byte 4....................................................................................66
8.5.18 (Address 45h; SETUP5) Setup Byte 5....................................................................................66
______________________________________________________________________________
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
5
Specification
NET2272 USB Peripheral Controller
8.5.19 (Address 46h; SETUP6) Setup Byte 6....................................................................................67
8.5.20 (Address 47h; SETUP7) Setup Byte 7....................................................................................67
8.6
ENDPOINT REGISTERS .................................................................................................................68
8.6.1
(Address 05h; EP_DATA) Endpoint Data .............................................................................68
8.6.2
(Address 06h; EP_STAT0) Endpoint Status Register (low byte) ...........................................68
8.6.3
(Address 07h; EP_STAT1) -- Endpoint Status Register (high byte) ......................................69
8.6.4
(Address 08h; EP_TRANSFER0) Transfer Count Register (Byte 0) .....................................69
8.6.5
(Address 09h; EP_TRANSFER1) Transfer Count Register (Byte 1) .....................................69
8.6.6
(Address 0Ah; EP_TRANSFER2) Transfer Count Register (Byte 2) .....................................69
8.6.7
(Address 0Bh; EP_IRQENB) Endpoint Interrupt Enable Register........................................70
8.6.8
(Address 0Ch: EP_AVAIL0) Endpoint Available Count (low byte).......................................70
8.6.9
(Address 0Dh: EP_AVAIL1) Endpoint Available Count (high byte) .....................................70
8.6.10 (Address 0Eh; EP_RSPCLR) Endpoint Response Register Clear .........................................71
8.6.11 (Address 0Fh; EP_RSPSET) Endpoint Response Register Set ..............................................72
8.6.12 (Address 28h; EP_MAXPKT0) Max Packet Size (low byte) ..................................................72
8.6.13 (Address 29h; EP_MAXPKT1) Max Packet Size (high byte).................................................72
8.6.14 (Address 2Ah; EP_CFG) Endpoint Configuration Register ..................................................73
8.6.15 (Address 2Bh: EP_HBW) Endpoint High Bandwidth............................................................73
8.6.16 (Address 2Ch: EP_BUFF_STATES) Endpoint Buffer States.................................................74
8.7
REGISTER CHANGES FROM NET2270...........................................................................................74
9
USB STANDARD DEVICE REQUESTS..........................................................................................75
9.1
CONTROL ‘READ’ TRANSFERS ....................................................................................................76
9.1.1
Get Device Status...................................................................................................................76
9.1.2
Get Interface Status ...............................................................................................................76
9.1.3
Get Endpoint Status ...............................................................................................................76
9.1.4
Get Device Descriptor (18 Bytes) ..........................................................................................76
9.1.5
Get Device Qualifier (10 Bytes).............................................................................................77
9.1.6
Get Other_Speed_Configuration Descriptor .........................................................................77
9.1.7
Get Configuration Descriptor................................................................................................78
9.1.8
Get String Descriptor 0..........................................................................................................81
9.1.9
Get String Descriptor 1..........................................................................................................81
9.1.10 Get String Descriptor 2..........................................................................................................81
9.1.11 Get String Descriptor 3..........................................................................................................81
9.1.12 Get Configuration..................................................................................................................81
9.1.13 Get Interface ..........................................................................................................................81
9.2
CONTROL ‘WRITE’ TRANSFERS ...................................................................................................82
9.2.1
Set Address.............................................................................................................................82
9.2.2
Set Configuration...................................................................................................................82
9.2.3
Set Interface ...........................................................................................................................82
9.2.4
Device Clear Feature.............................................................................................................82
9.2.5
Device Set Feature.................................................................................................................82
9.2.6
Endpoint Clear Feature .........................................................................................................83
9.2.7
Endpoint Set Feature .............................................................................................................83
10
ELECTRICAL SPECIFICATIONS ..............................................................................................84
10.1
ABSOLUTE MAXIMUM RATINGS ..................................................................................................84
10.2
RECOMMENDED OPERATING CONDITIONS ..................................................................................84
10.3
DC SPECIFICATIONS ....................................................................................................................85
10.3.1 Core DC Specifications .........................................................................................................85
10.3.1.1
10.3.1.2
10.3.1.3
10.3.1.4
10.3.1.5
10.3.1.6
Disconnected from USB...................................................................................................................85
Connected to USB (High-Speed) .....................................................................................................85
Active (High-Speed) ........................................................................................................................85
Connected to USB (Full-Speed).......................................................................................................85
Active (Full-Speed)..........................................................................................................................85
Suspended ........................................................................................................................................85
______________________________________________________________________________
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
6
Specification
NET2272 USB Peripheral Controller
10.3.2 USB Full Speed DC Specifications ........................................................................................86
10.3.3 USB High Speed DC Specifications.......................................................................................86
10.3.4 Local Bus DC Specifications .................................................................................................87
10.4
AC SPECIFICATIONS ....................................................................................................................88
10.4.1 USB Full Speed Port AC Specifications ................................................................................88
10.4.2 USB High Speed Port AC Specifications ...............................................................................88
10.4.3 USB Full Speed Port AC Waveforms.....................................................................................89
10.4.4 USB Port AC/DC Specification Notes ...................................................................................91
10.4.5 Local Bus Non-Multiplexed Read ..........................................................................................92
10.4.6 Local Bus Multiplexed Read ..................................................................................................93
10.4.7 Local Bus Non-Multiplexed Write .........................................................................................94
10.4.8 Local Bus Multiplexed Write .................................................................................................95
10.4.9 Local Bus DMA Read; Slow Mode ........................................................................................96
10.4.10
Local Bus DMA Read; Fast Mode ....................................................................................97
10.4.11
Local Bus DMA Read; Burst Mode...................................................................................98
10.4.12
Local Bus DMA Write; Slow Mode ...................................................................................99
10.4.13
Local Bus DMA Write; Fast Mode..................................................................................100
10.4.14
Local Bus DMA Write; Burst Mode ................................................................................101
11
MECHANICAL DRAWING ........................................................................................................102
______________________________________________________________________________
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
7
Specification
NET2272 USB Peripheral Controller
1 Introduction
1.1
Features
•
USB Specification Version 2.0 Compliant (high and full speed)
•
Interfaces between a local CPU bus and a USB bus
•
Supports USB Full Speed (12 Mbps) and High Speed (480 Mbps)
•
Supports optional Split Bus DMA, with dedicated DMA and CPU access
•
Provides 3 Configurable Physical Endpoints, in addition to Endpoint 0
•
Provides 30 Configurable Virtual Endpoints
•
Each endpoint can be Isochronous, Bulk, or Interrupt, as well as IN or OUT
•
Supports high-bandwidth isochronous mode
•
Supports Max Packet Size up to 1K bytes, double buffered
•
Internal 3 Kbyte memory provides transmit and receive buffers
•
Local CPU bus easily interfaces to generic CPUs
•
8-bit or 16-bit CPU or DMA bus transfers
•
Multiple register address modes supports both direct and indirect register addressing
•
Automatic retry of failed packets
•
Diagnostic register allows forced USB errors
•
Software controlled disconnect allows re-enumeration
•
Atomic operation to set and clear status bits, simplifying software
•
Low power CMOS in 64 Pin Plastic TQFP Package
•
30 MHz oscillator with internal phase-lock loop multiplier
•
Provides an output clock to the local bus - 8 programmable frequencies from OFF to 60 MHz
•
2.5V, 3.3V operating voltages with 5V tolerant I/O
1.2
Overview
The NET2272 USB Peripheral Controller allows control, isochronous, bulk and interrupt transfers
between a local bus and a Universal Serial Bus (USB). The NET2272 supports the Device side of a
connection between a USB host computer and intelligent peripherals such as image scanners, printers,
and digital cameras.
The six main modules of the NET2272 are the USB Transceiver, Serial Interface Engine, USB Protocol
Controller, Endpoint Packet Buffers, Local Bus Interface, and the Configuration Registers.
USB Transceiver:
• Supports Full Speed (12 Mbps) or High Speed (480 Mbps) operation
• Serial data transmitter and receiver
• Parallel data interface to SIE
• Single parallel data clock output with on-chip PLL to generate higher speed serial data clocks
• Data and clock recovery from USB serial data stream
• SYNC/EOP generation and checking
• Bit-stuffing/unstuffing; bit stuff error detection
• Logic to facilitate Resume signaling
• Logic to facilitate Wake Up and Suspend detection
• Ability to switch between Full-Speed and High-Speed terminations/signaling
______________________________________________________________________________
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
8
Specification
NET2272 USB Peripheral Controller
Serial Interface Engine (SIE):
• Interface between Packet Buffers and USB transceiver
• CRC generator and checker
• Packet Identifier (PID) decoder
• Forced Error Conditions
• USB 2.0 Test Modes
USB Protocol Controller
• Host to Device Communication
• Automatic retry of failed packets
• Up to 3 Isochronous, Bulk, or Interrupt physical endpoints, each with a configurable packet buffer
• Up to 30 virtual endpoints can be mapped to the physical endpoints
• Configurable Control Endpoint 0
• Interface to packet buffers
• Software controlled disconnect signaling allows device enumeration
• Software control of USB suspend and root port reset detection
• Software controlled device remote wakeup
• Software control of root port wakeup
Endpoint Packet Buffers
• Choice from 4 preset configurations simplify programming
• Separate 128 byte, packet buffer for physical endpoint 0
• 3 Kbytes of configurable packet buffer memory for physical endpoints A, B, and C
• Supports Max Packet Size up to 1K bytes, double buffered
Local Bus Interface
• Provides slave interfaces to 8-bit or 16-bit CPU
• Provides access to internal Transmit and Receive packet buffers.
• Supports Split DMA transactions (DMA and CPU on separate data bus)
• Supports DMA burst mode.
• Local interface supports both DMA and Interrupt transfers
• Supports optional multiplexed Address/Data bus using ALE for low pin count applications
• Supports indirect addressing, allowing access to all registers with only a single address bit
• Supports 5V tolerant I/O
Configuration Registers
• Internal registers are accessible from the local bus
• Main registers for common functions
• USB Registers for the USB Interface Module
• Control registers for each endpoint
______________________________________________________________________________
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
9
Specification
1.3
NET2272 USB Peripheral Controller
NET2272 Block Diagram
USB
USB 2.0
Transceiver
Serial
Interface
Engine
(SIE)
USB
Protocol
Controller
Configuration
Registers
Local Bus
Interface
Local Bus
Packet
Buffer
1.4
NET2272 Typical System Block Diagrams
USB Cable
USB
Connector
NET2272
USB
Controller
CPU
RAM
DMA
ROM
Application
Interface
CPU-based Device Controller
______________________________________________________________________________ 10
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
USB Cable
USB
Connector
CPU
NET2272
USB
Controller
Split Bus DMA
ASIC
(with embedded DMA)
ROM
RAM
ASIC with Split Bus DMA
______________________________________________________________________________ 11
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
1.5
NET2272 USB Peripheral Controller
Example connections to NET2272
2.5VCC 3.3VCC
2.5VCCA
NOTE: For 16-bit bus, use address bits 5:1;
For 8-bit bus, use address bits 4:0.
TEST
TRST
TMC2
LCLKO
DREQ
IRQ#
XIN
RSDM
DM
Y1
1
2
J1
2 39.2 +/- 1%
USBVCC
RPU
6
5
R4
1
2 39.2 +/- 1%
2
R2
1
2 1.5K
L1
GND2
GND1
AVSS1
AVSS2
COM
VBUS
42 ohm
4
10
12
14
16
24
56
33
41
54
N2272
0.01uF
2
VBUSL
R7
1
47K
2
2.5VCCA
2.5VCCA
1uH
2.5VCC
0.1uF
C13
0.01uF
1
1
C12
10uF
1
1
C11
C14
0.1uF
+
C15
0.01uF
C16
10uF
2
0.01uF
1
+
C10
2
0.1uF
2
C9
2
0.01uF
2
C8
1
1
0.1uF
2
C7
10uF
1
C6
2
0.01uF
1
+
C5
2
0.1uF
2
2
C4
2
1
1uH
DIGITAL
GROUND
3.3VCC
2
1
L4
1
1
2
L3
2
1
1
2.5VCC
1
2
3
4
GND
USB_B
C3
R6
1M
L2
42 ohm
2
2.43K +/- 1%
1
1
2
3
4
5
USBLGND
USBCGND
2
RREF
VSSC1
VSSC2
VSSIO1
VSSIO2
VSSIO3
64
R5
DREQ
IRQ#
R3
9
8
1
13
DP
RSDP
2
1
2
1
2
10pF
RREF
C2
10pF
1K
XOUT
30 MHz
C1
R1
2
26
1
CLOCK_OUT
C
2
2
57
62
63
3.3VCC
TP1
1
RESET#
ALE
CS#
IOR#
IOW#
DMARD#
DMAWR#
DACK
EOT
1
25
LD0
LD1
LD2
LD3
LD4
LD5
LD6
LD7
LD8
LD9
LD10
LD11
LD12
LD13
LD14
LD15
1
18
40
17
LA0
LA1
LA2
LA3
LA4
LD0
LD1
LD2
LD3
LD4
LD5
LD6
LD7
LD8
LD9
LD10
LD11
LD12
LD13
LD14
LD15
1
58
53
61
59
60
50
34
51
52
RESET#
ALE
CS#
IOR#
IOW#
DMARD#
DMAWR#
DACK
EOT
LD[15:0]
19
20
21
22
23
35
36
37
38
39
43
44
45
46
47
49
1
32
31
30
29
28
VDDC1
VDDC2
VDDIO1
VDDIO2
VDDIO3
VDD25
VDD33
AVDD
PVDD
LA1
LA2
LA3
LA4
LA5
1
48
27
42
55
3
7
15
11
U?
LA[5:1]
ANALOG
GROUND
______________________________________________________________________________ 12
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
1.5.1 Example Part Numbers
Part
30 MHz Fundamental
Crystal (Y1)
Ferrite Beads (L1-L2)
1 µH Inductor, 10%, 0805
Pkg (L3-L4)
2.43K, 1% resistor, 0.1
Watt, 0603 Pkg
(R5)
USB B Connector
Manufacturer
KDS
Part Number
AT-49 30.000-16
Website
http://www.kdsj.co.jp/english.html
Taiyo Yuden
Taiyo Yuden
FBMJ2125HS420-T
LK21251R0K
http://www.t-yuden.com/ferritebeads/index.cfm
http://www.t-yuden.com/inductors/index.cfm
Panasonic
ERJ6ENF2431V
Newnex
URB-1001
http://www.panasonic.com/industrial/compone
nts/pdf/002_er13_erj_2r_3r_6r_3e_6e_8e_14_
12_dne.pdf
http://www.newnex.com
Note that the crystal should have a tolerance of +/- 0.005% (50 ppm) to guarantee a data rate of 480 Mbps +/- 500
ppm.
1.5.2
General PCB Layout Guidelines
USB2.0 high-speed 480 Mbits/sec data transfers utilize 400 mV differential signaling. This requires special Printed
Circuit Board layout requirements. Intel provides some USB layout guidelines in the following document:
http://www.usb.org/developers/docs/hs_usb_pdg_r1_0.pdf. In addition, NetChip provides the following guidelines:
The following guidelines must be followed to insure proper operation of the NET2272. It is
strongly suggested that schematics and PCB layout be submitted to [email protected]
for review prior to PCB fabrication.
1.5.2.1 USB Differential Signals
•
•
•
•
•
•
•
•
•
Consult with board manufacturer for determining layer separation, trace width, and trace separation for
maintaining differential impedance of 90 ohms.
Maintain equal trace lengths for D+ and D-.
Minimize number of vias and curves on D+ and D- traces.
Use two 45 degree turns instead of one 90 degree turn.
Minimize trace lengths shown in bold in the schematic in section 1.5.
Prevent D+ and D- traces from crossing a power plane void. The same ground layer shall be kept next to
the D+ and D- traces.
Digital Ground (VSS) layer should be placed next to the layer where D+ and D- are routed.
Avoid using studs or test points for observing USB signals.
Maximize the distance of D+ and D- from other signals to prevent crosstalk.
1.5.2.2 Analog VDD (power)
•
•
•
•
Analog power must be filtered from the digital power using the recommended circuit provided.
Analog VDD and digital VDD must be connected via 1µH inductor.
Analog VDD must be separated from digital VDD. If analog VDD and digital VDD are in the same layer,
split the layer to accommodate the two power signals.
AVDD and PVDD pins should be connected to analog VDD.
______________________________________________________________________________ 13
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
1.5.2.3 Analog VSS (ground)
•
•
•
Analog ground must be filtered from the digital ground using the recommended circuit provided.
Analog VSS and digital VSS must be connected via a 1µH inductor.
AVSS, PVSS, COM pins, and RREF’s resistor should be connected to analog VSS.
1.5.2.4 Decoupling Capacitors
•
•
•
•
•
At least one 0.1µF decoupling capacitor for every two pairs of digital/analog VDD and VSS should be
located near the NET2272 device.
At least one 0.01µF decoupling capacitor for every two pairs of digital/analog VDD and VSS should be
located near the NET2272 device.
Decoupling capacitors may be placed on the solder side of the PCB.
At least one 10µF filter capacitor for every five 0.1µF or 0.01µF decoupling capacitors.
Use capacitors that have good quality at high frequency for low ESR, such as tantalum or ceramic
capacitors. Do not use electrolytic capacitors.
1.5.2.5 EMI Noise Suppression
•
•
•
•
1.6
A common-mode choke coil may suppress EMI noise effectively, although such a coil could affect USB
2.0 signal quality.
Choose a good quality noise filter, if necessary.
For a typical implementation, a choke is not required.
Use good quality, shielded cables.
Terminology
Byte. 8-bit quantity of data.
Word. 16-bit quantity of data.
Scalar. Multi-byte data element.
Local Transaction. A read or write operation on the local bus. It includes an address phase followed by one data
transfer.
Local Transfer. During a transfer, data is moved from the source to the destination on the local bus.
Clock cycle. One period of the internal 60 MHz clock.
Big Endian. The most significant byte in a scalar is located at address 0.
Little Endian. The least significant byte in a scalar is located at address 0.
______________________________________________________________________________ 14
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
2 Pin Description
Abbreviation
I
O
I/O
S
TS
TP
OD
PD
PU
#
Description
Input
Output
Bi-directional
Schmitt Trigger
Tri-State
Totem-Pole
Open-Drain
50K Pull-Down
50K pull-up
Active low
NOTE: Input pins that do not have an internal pull-up or pull-down resistor (designated by PU or PD in the ‘Type’
column below) must be driven externally when the NET2272 is in the suspended state.
2.1
Digital Power & Ground (10 pins)
Signal Name
Pin
Type
Description
VDDC
1, 48
Power
Digital Core Supply Voltage. Connect to 2.5V.
VSSC
24, 56
GND
Digital Core Ground. Connect to GND.
VDDIO
27, 42, 55
Power
I/O Interface Supply Voltage. Connect to 3.3V.
VSSIO
33, 41, 54
GND
I/O Interface Ground. Connect to GND.
______________________________________________________________________________ 15
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
2.2
NET2272 USB Peripheral Controller
USB Transceiver (15 pins)
Signal Name
Pin
Type
Description
DP
6
I/O
High Speed USB Positive Data Port.
DP is the high speed positive differential data signal of the USB data port.
It also acts as the full speed positive differential input data port. This pin
connects directly to the USB connector.
DM
8
I/O
High Speed USB Negative Data Port.
DM is the high speed negative differential data signal of the USB data
port. It also acts as the full speed negative differential input data port.
This pin connects directly to the USB connector.
RSDP
5
O
Full Speed USB Positive Output Data Port.
RSDP is the full speed positive differential output data signal of the USB
data port. This pin connects through a 39.2 ohm +/- 1% resistor to the
USB connector.
RSDM
9
O
Full Speed USB Negative Output Data Port.
RSDM is the full speed negative differential output data signal of the USB
data port. This pin connects through a 39.2 ohm +/- 1% resistor to the
USB connector.
RPU
2
O
DP Pull Up Resistor. Connect to DP pin through a 1.5K resistor.
RREF
13
I
Reference Resistor. Connect 2.43K +/- 1% resistor to analog ground.
The typical voltage on this pin is 1.27 volts.
VDD25
3
Power
Supply Voltage. Connect to digital 2.5 V.
VDD33
7
Power
Supply Voltage. Connect to digital 3.3 V.
PVDD
11
Power
PLL Supply Voltage. Connect to analog 2.5 V.
AVDD
15
Power
Analog Supply Voltage. Connect to analog 2.5 V.
GND
4,10
Ground
Digital Ground. Connect to ground.
AVSS
12, 14
Ground
Analog Ground. Connect to analog ground.
16
Ground
PLL Ground. Connect to analog ground.
COM (AVSS)
______________________________________________________________________________ 16
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
2.3
NET2272 USB Peripheral Controller
Clocks, Reset, Misc. (8 pins)
Signal Name
Pin
Type
Description
XIN
25
I
Oscillator input. Connect to 30 MHz crystal or external oscillator
module.
XOUT
26
O
Oscillator output. Connect to crystal, or leave open if using an external
oscillator module. The oscillator stops when the device is suspended.
LCLKO
57
O,
12mA,
TS
Local Clock Output. This pin is a buffered clock output from the internal
PLL, with the frequency depending on the state of the Local Clock Output
field in the LOCCTL configuration register. This pin stops oscillating as
soon as the NET2272 is put into suspend mode, and is not driven while the
device is suspended. When the internal oscillator is started, LCLKO is
prevented from being driven for 2 msec. LCLKO doesn’t oscillate while
the chip is in the power-down mode.
RESET#
58
I, S
Reset. External reset. Connect to local or power-on reset. To reset when
oscillator is stopped (initial power-up or in suspend state), assert for at
least two milliseconds. When oscillator is running, assert for at least five
60 MHz clock periods.
VBUS
64
I, S
USB VBUS. This input indicates when the NET2272 is connected to a
powered-up USB host connector. An external 47K pull-down resistor
should be connected to this pin to keep it low when not connected to the
USB.
TEST
18
I
Test input. Connect to ground for normal operation.
TRST
40
I
TRST Test input. TAP controller reset. Connect to ground for normal
operation.
TMC2
17
I
TMC2 Test input. I/O buffer control. Connect to ground for normal
operation.
______________________________________________________________________________ 17
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
2.4
NET2272 USB Peripheral Controller
Local Bus Pin Descriptions (31 pins)
Signal Name
Pin
Type
Description
28-32
I
Address Bus. Five bits of address can directly address most of the
internal registers of the NET2272. A minimum of 1 address bit is required
to operate the NET2272, using an optional Register-Indirect mode. A
third addressing mode (multiplexed address and data) uses ALE with
LD[4:0] to provide 5 bits of register addressing.
53
I
Address Latch Enable. When operating in Multiplexed Address and
Data mode, the 5-bit address bus is latched on the trailing (negative) edge
of ALE. The NET2272 will automatically detect use of the ALE pin to
indicate use of multiplexed address and data on the LD[4:0] pins.
49, 47-43,
39-35,
23-19
I/O,
6mA
Data Bus. These pins serve as the input and output data bus for the local
CPU. In multiplexed address/data mode, ALE can be used with LD[4:0]
to provide 5-bits of address on the falling edge of ALE. In 16-bit mode,
the data bus is 16-bits wide.
IOR#
59
I
Read Strobe. The local bus master asserts this signal during a read
transaction.
IOW#
60
I
Write Strobe. The local bus master asserts this signal during a write
transaction.
IRQ#
63
O,
12mA,
OD
Interrupt Request Output. This signal interrupts the local processor
based on events selected in internal program registers. Since this pin is
open-drain, an external 1K pull-up resistor is required.
CS#
61
I
Chip Select. This signal enables access to registers within the NET2272.
Asserting this pin during suspend will cause the device to wake up.
Asserting this pin during RESET# holds the NET2272 in a low-power
mode by disabling the internal oscillator.
DMAWR#
34
I
DMA Write Strobe. The DMA bus master asserts this signal during a
DMA write transaction when split-bus DMA is selected.
DMARD#
50
I
DMA Read Strobe. The DMA bus master asserts this signal during a
DMA read transaction when split-bus DMA is selected
DREQ
62
O,
3mA,
TS
DMA Request. This signal requests DMA transfers from an external
DMA controller. This output floats when the USB Host suspends the
device. The polarity of this signal is programmable.
DACK
51
I
DMA Acknowledge. Used to transfer data to/from the packet buffer in
response to DREQ. This pin is ignored unless the DMA DACK Enable bit
in the LOCCTL1 register is set. The polarity of this signal is
programmable.
EOT
52
I
End of Transfer. This signal from an external DMA controller is used to
terminate a DMA transfer. The current word will be transferred, but no
additional transfers will be requested. EOT can be programmed to cause
an interrupt. The polarity of this signal is programmable.
LA[4:0]
ALE
LD[15:0]
______________________________________________________________________________ 18
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
VDDC
LD14
LD13
LD12
LD11
LD10
VDDIO
VSSIO
TRST
LD9
LD8
LD7
LD6
LD5
DMAWR#
VSSIO
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
Physical Pin Assignment
48
2.5
NET2272 USB Peripheral Controller
LD15
49
32
LA0
DMARD#
50
31
LA1
DACK
51
30
LA2
EOT
52
29
LA3
ALE
53
28
LA4
VSSIO
54
27
VDDIO
VDDIO
55
26
XOUT
VSSC
56
25
XIN
LCLKO
57
24
VSSC
RESET#
58
23
LD4
IOR#
59
22
LD3
IOW#
60
21
LD2
CS#
61
20
LD1
DREQ
62
19
LD0
IRQ#
63
18
TEST
VBUS
64
17
TMC2
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
VDDC
RPU
VDD25
GND
RSDP
DP
VDD33
DM
RSDM
GND
PVDD
AVSS
RREF
AVSS
AVDD
COM
NetChip
NET2272
XXXXXXX
REVx
Note: This drawing is for informational purposes only. Please contact NetChip for additional chip marking, PCB
layout and manufacturing information.
______________________________________________________________________________ 19
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
3 Reset and Initialization
3.1
Overview
The NET2272 normal initialization sequence consists of the following:
• Assert/De-Assert RESET# pin
• Local CPU initializes USB and local bus configuration registers
3.2
RESET# Pin
The RESET# pin causes all logic in the NET2272 to be set to its default state. It is typically connected to a poweron reset circuit.
3.3
Root Port Reset
If the NET2272 detects a single-ended zero on the root port for greater than 2.5 microseconds, it is interpreted as a
root port reset. The root port reset is only recognized if the VBUS input pin is high, and the USB Detect Enable bit
in the USBCTL0 register is set. The following resources are reset:
•
•
•
•
•
Serial Interface Engine (SIE)
USB state machines
Local state machines
OURADDR Register
Buffer pointers
The root port reset does not affect the remainder of the configuration registers. The Root Port Reset Interrupt bit is
set when a change in the root port reset has been detected. The local CPU should take appropriate action when this
interrupt occurs.
According to the USB Specification, the width of the USB reset is minimally 10ms and may be longer depending on
the upstream host or hub. There is no specified maximum width for the USB reset.
3.4
Reset Summary
The following table shows which device resources are reset when each of the 2 reset sources are asserted.
Device
Resources
Reset Sources
RESET# pin
USB Root Port Reset
USB, SIE
modules,
OURADDR,
registers
All
Configuration
Registers
X
X
X
Endpoint
Buffer
Pointers
X
X
______________________________________________________________________________ 20
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
4 Local Bus Interface
4.1
Introduction
The Local Bus Interface allows the NET2272 to be easily interfaced with many generic processors and custom ASIC
interfaces. Both multiplexed and non-multiplexed buses are supported.
4.2
Register Addressing Modes
Several addressing methods are provided in the NET2272 in order to support various user architectures. These
modes are always active and nothing special needs to be done to use them. These modes act on a transaction-bytransaction basis, allowing DMA and CPU to operate with inherently different bus architectures. For instance, the
CPU could operate with a multiplexed bus (using ALE to de-multiplex the Address/Data bus) while the DMA could
operate using a non-multiplexed Data bus.
4.2.1 Direct Address Mode
Direct Address Mode uses LA[4:0] to directly access the first 32 configuration registers.
4.2.2 Indirect Address Mode
Indirect Address mode uses registers REGADDRPTR (address 0x00) and REGDATA (address 0x01) to provide a
Command/Data interface to the NET2272 internal registers and buffers. All CPU transactions performed with
REGDATA will have their address sourced by REGADDRPTR. The local CPU first programs REGADDRPTR
with the desired register address, then reads or writes to REGDATA with the data intended for the register pointed
to by REGADDRPTR. This method of register addressing requires only 1 physical address bit (to access address
0x00 or address 0x01). All unused address bits of the NET2272 should be connected to ground. When all five
address bits are being used, this addressing method allows access to registers above address 1Fh.
4.2.3 Multiplexed Address Mode
Multiplexed Address mode uses the ALE pin to de-multiplex the desired address from the data bus. The NET2272
automatically detects the use of ALE and will use the address represented by LD[4:0] on the falling edge of ALE as
the address of the current transaction. This addressing mode is supported by several common microcontrollers.
ALE should be grounded if this mode is not used.
4.3
Control Signal Definitions
The control signals direct the flow of data across the local bus. A write transaction is performed by asserting CS#
and IOW#. The Address and Data must be valid on the trailing (rising) edge of IOW#. A read transaction is
performed by asserting CS# and IOR#.
4.4
Bus Width / Byte Alignment
The local bus supports 8 or 16-bit buses. In 8-bit mode, all configuration registers and the buffers are accessed one
byte at a time. A typical 8-bit application would connect the CPU address bits A[4:0] to the NET2272 address bus
LA[4:0].
In 16-bit mode, the configuration registers are still accessed a byte at a time, but the buffers are accessed a word at a
time. The Byte Swap bit in the LOCCTL configuration register determines whether the bytes are swapped as they
are being written into the buffer in 16-bit mode. This allows for connections to little or big endian processors. A
typical 16-bit application would connect the CPU address bits A[5:1] to the NET2272 address bus LA[4:0].
______________________________________________________________________________ 21
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
4.5
NET2272 USB Peripheral Controller
I/O Transactions
I/O transactions are those in which a CPU on the local bus accesses registers or packet buffers within the NET2272.
4.5.1 Non-Multiplexed I/O Read
Non-multiplexed I/O read transactions are started when both CS# and IOR# are asserted. The address must be valid
T4 before CS# and IOR# are both asserted. Valid read data is driven onto the data bus within T6 after CS# and
IOR# are both asserted. The read transaction ends and the data bus floats when either CS# or IOR# are de-asserted.
A new I/O read transaction cannot be started until the T8A recovery time has expired, and a new I/O write
transaction cannot be started until the T8B recovery time has expired. ALE must be held low for non-multiplexed
mode.
0ns
25ns
50ns
75ns
NetChip Technology; NET2272; Non-Multiplexed I/O Read; 8/19/02; IORD.TD
LA[4:0]
A0
A1
CS#
IOR#
LD[15:0]
D0
D1
4.5.2 Multiplexed I/O Read
Multiplexed I/O reads are started when the address is driven onto the lower bits of the data bus, and ALE is pulsed.
Once the address has been latched into the NET2272, the data phase is initiated with the assertion of both CS# and
IOR#. To prevent bus contention on the data bus, CS# and IOR# should not be asserted until the local bus master
has tri-stated the address. Valid read data is driven onto the data bus within T6 after CS# and IOR# are both
asserted. The read transaction ends and the data bus floats when either CS# or IOR# are de-asserted. A new I/O
read transaction cannot be started until the T8A recovery time, has expired, and a new I/O write transaction cannot
be started until the T8B recovery time has expired.
0ns
25ns
50ns
75ns
100ns
NetChip Technology; NET2272; Multiplexed I/O Read; 08/19/02; IORD_MPX.TD
ALE
CS#
IOR#
LD[15:0]
A0
D0
A1
D1
______________________________________________________________________________ 22
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
4.5.3 Non-Multiplexed I/O Write
Non-multiplexed I/O writes are started when both CS# and IOW# are asserted. The address and write data must
meet the setup time with respect to the end of the write transaction. Data is written into the register or packet buffer
when either CS# or IOW# are negated. A new I/O write transaction cannot be started until the T15A recovery time
has expired, and a new I/O read transaction cannot be started until the T15B recovery time has expired. ALE must
be held low for non-multiplexed mode.
0ns
10ns
20ns
30ns
40ns
50ns
NetChip Technology; NET2272; Non-Multiplexed I/O Write; 8/19/02; IOWR.TD
LA[4:0]
A0
A1
LD[15:0]
D0
D1
CS#
IOW#
4.5.4 Multiplexed I/O Write
Multiplexed I/O writes are started when the address is driven onto the lower bits of the data bus, and ALE is pulsed.
Once the address has been latched into the NET2272, the data phase is initiated with the assertion of both CS# and
IOW#. The write data must meet the setup time with respect to the end of the write cycle. Data is written into the
register or packet buffer when either CS# or IOW# are negated. A new I/O write transaction cannot be started until
the T15A recovery time has expired, and a new I/O read transaction cannot be started until the T15B recovery time
has expired.
0ns
10ns
20ns
30ns
40ns
50ns
60n
NetChip Technology; NET2272; Multiplexed I/O Write; 8/19/02; IOWR_MPX.TD
ALE
LD[15:0]
A0
D0
A1
D1
CS#
IOW#
______________________________________________________________________________ 23
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
4.5.5 I/O Performance
4.5.5.1 Non-Multiplexed Read Transaction
•
•
•
•
Read Access Time (T6): 18 nsec
Read Recovery Time (T8): 19 nsec
For an 8-bit bus, the maximum performance is:
1/37 nsec = 27 Mbytes/sec
For a 16-bit bus, the maximum performance is:
2/37 nsec = 54 Mbytes/sec
4.5.5.2 Multiplexed Read Transaction
•
•
•
•
•
•
ALE Width (T3): 5 nsec
ALE to Read Command (T19): 1 nsec minimum
Read Access Time (T6): 18 nsec
Read Recovery Time (T8): 19 nsec
For an 8-bit bus, the maximum performance is:
1/43 nsec = 23 Mbytes/sec
For a 16-bit bus, the maximum performance is:
2/43 nsec = 46 Mbytes/sec
4.5.5.3 Non-Multiplexed Write Transaction
•
•
•
•
Write Width (T12): 5 nsec
Write to Write Recovery Time (T15A): 28 nsec
For an 8-bit bus, the maximum performance is:
1/33 nsec = 30 Mbytes/sec
For a 16-bit bus, the maximum performance is:
2/33 nsec = 60 Mbytes/sec
4.5.5.4 Multiplexed Write Transaction
•
•
•
•
•
•
ALE Width (T3): 5 nsec
ALE to Write Command (T19): 1 nsec minimum
Write Width (T12): 5 nsec
Write to Write Recovery Time (T15A): 28 nsec
For an 8-bit bus, the maximum performance is:
1/39 nsec = 25 Mbytes/sec
For a 16-bit bus, the maximum performance is:
2/39 nsec = 50 Mbytes/sec
______________________________________________________________________________ 24
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
4.6
NET2272 USB Peripheral Controller
DMA Transactions
DMA transfers are those in which an external DMA controller transfers data between memory and one of the packet
buffers within the NET2272. DMA transfers can be configured for endpoint A or endpoint B only. The local CPU
handles transfers to/from endpoints 0 and C. The external DMA controller is programmed to perform fly-by
demand mode transfers. In this mode, transfers occur only when the NET2272 requests them and the data is
transferred between the NET2272 and local memory during the same bus transaction.
During DMA transactions, the endpoint buffer is determined by the DMA Endpoint Select field of the DMAREQ
register. During CPU transactions, the endpoint buffer is determined by the Page Select field of the PAGESEL
register. In split DMA mode, CPU accesses to one endpoint buffer can occur simultaneously with DMA accesses to
another endpoint buffer.
4.6.1 DMA Read
For OUT transfers (host to device), the local and host CPUs first arrange to transfer a block of data from host
memory to local memory. The local CPU programs the external DMA controller to transfer the desired number of
bytes. The signals DREQ, DACK, IOR#, and EOT are used to control the transactions between the external DMA
controller and the NET2272. DREQ and DACK are minimally needed to exchange data with the NET2272 since
the direction (read) is established by the Endpoint Direction bit in the EP_CFG register. The mode of operation is
set by the DMA Control DACK bit in the DMAREQ register. If the DMA Control DACK bit is high, then both
DACK and IOR# are needed by the NET2272 for a DMA read. If the DMA Control DACK bit is low, then only
DACK is needed.
The local CPU programs the NET2272 DMAREQ register to associate the DMA with a NET2272 endpoint (either
Endpoint A or Endpoint B). Transfers occur only when the NET2272 requests them, after the DMA Request Enable
bit is set in the DMAREQ register.
When the NET2272 has data available in an endpoint buffer, and that endpoint has been assigned to the DMA
channel, the DMA request (DREQ) signal is asserted. The external DMA controller then requests the local bus from
the local bus master. After the external DMA controller has been granted the bus, it drives a valid memory address
and asserts DACK, IOR# (optional), and MEMW# (to memory), thus transferring a byte from an endpoint’s buffer
to local memory. In DMA slow mode, the NET2272 de-asserts DREQ within T20 after the start of the transaction,
while in fast mode, it de-asserts DREQ at the start of the transaction. If there is still data in the buffer, the NET2272
then re-asserts DREQ. The DMA transfers continue until the DMA byte count reaches zero or the EOT pin is
asserted during the last DMA transfer. The DMA Done Interrupt bit in the IRQSTAT0 register will be set for the
following conditions:
• The EOT pin is asserted during the last DMA transfer.
• The local CPU writes a zero to the EP_TRANSFER register after the DMA has finished.
If DMA Burst Mode is selected, DREQ is asserted when there is data in the buffer and the DMA is enabled. It
remains asserted until the FIFO becomes empty, the DMA is disabled, or the EOT pin is asserted.
______________________________________________________________________________ 25
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
4.6.1.1 Slow DMA Read Timing
In this mode, DREQ is de-asserted within T20 after the beginning of the read transaction. It is then re-asserted
within T21 after the end of the read transaction.
0ns
50ns
100ns
150ns
NetChip Technology; NET2272; Slow Mode DMA Read; 08/19/02; DMARD.TD
DREQ
DACK#
IOR# (Optional)
LD[15:0]
D0
D1
EOT# (Optional)
4.6.1.2 Fast DMA Read Timing
In this mode, DREQ is de-asserted at the beginning of the read transaction. It is then re-asserted either at the end of
the read transaction if the read enable width is greater than T21, or at T21 after the beginning of the read transaction
if the read enable width is less than T21.
0ns
25ns
50ns
75ns
100ns
NetChip Technology; NET2272; Fast Mode DMA Read; 08/19/02; DMARD_FAST.TD
DREQ
DACK#
IOR# (Optional)
LD[15:0]
D0
D1
D2
EOT# (Optional)
4.6.1.3 Burst DMA Read Timing
In this mode, DREQ remains asserted until the DMA transfer completes.
0ns
25ns
50ns
75ns
100ns
NetChip Technology; NET2272; Burst Mode DMA Read; 09/04/02; DMARD_BURST.TD
DREQ
DACK#
IOR# (Optional)
LD[15:0]
D0
D1
D2
EOT# (Optional)
______________________________________________________________________________ 26
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
4.6.2 DMA Write
For IN transfers (device to host), the local and host CPUs first arrange to transfer a block of data from local memory
to host memory. The local CPU programs the external DMA controller to transfer the desired number of bytes. The
NET2272 EP_TRANSFER register is also programmed with the desired transfer size (in bytes). The transfer size
programmed into the EP_TRANSFER register can span many packets, allowing a single DMA setup to transfer
multiple packets. The DMA Request signal (DREQ) is asserted anytime there is space available in the buffer. The
endpoint’s Max Packet Size register controls the maximum number of bytes transmitted to the host in a single
packet. A short packet will be sent if there are remaining bytes to be sent when all EP_TRANSFER bytes have
been written or when EOT has been asserted during the last DMA cycle.
The signals DREQ, DACK, IOW#, and EOT are used to control the transactions between the external DMA
controller and the NET2272. DREQ and DACK are minimally needed to exchange data with the NET2272 since
the direction (write) is established by the Endpoint Direction bit in the EP_CFG register. The mode of operation is
set by the DMA Control DACK bit in the DMAREQ register. If the DMA Control DACK bit is high, then both
DACK and IOW# are needed by the NET2272 for a DMA write. If the DMA Control DACK bit is low, then only
DACK is needed.
The local CPU programs the NET2272 DMAREQ register to associate the DMA with a NET2272 endpoint (either
Endpoint A or Endpoint B). Transfers occur only when the NET2272 requests them, after the DMA Request Enable
bit is set in the DMAREQ register.
As long as there is space available in the selected endpoint’s buffer, and there are still bytes to be transferred, the
NET2272 will request DMA transfers by asserting DREQ. The external DMA controller then requests the local bus
from the local CPU. After the DMA controller has been granted the bus, it drives DACK, IOW# (optional), and
MEMR# (to memory) to transfer a byte from memory to the endpoint’s buffer. For DMA slow mode, the NET2272
de-asserts DREQ within T20 after the start of the transaction while for DMA fast mode, the NET2272 de-asserts
DREQ at the beginning of the transaction. If there is still space in the buffer and there are more bytes to be
transferred, the NET2272 re-asserts DREQ.
The USB host sends an IN token to the NET2272 and starts an IN data transaction from the selected endpoint’s
buffer. The DMA transfers continue until EP_TRANSFER bytes have been transferred or EOT has been asserted.
The DMA Done Interrupt bit in the IRQSTAT0 register will be set for the following conditions:
• The EOT pin is asserted during the last DMA transfer.
• The EP_TRANSFER counter counts down to 0.
• The local CPU writes a zero to the EP_TRANSFER register after the DMA has finished.
If DMA Burst Mode is selected, DREQ is asserted when there is space in the buffer and the DMA is enabled. It
remains asserted until the FIFO becomes full, the DMA is disabled, the EP_TRANSFER counter counts down to 0,
or the EOT pin is asserted.
______________________________________________________________________________ 27
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
4.6.2.1 Slow DMA Write Timing
In this mode, DREQ is de-asserted within T20 after the beginning of the write transaction. It is then re-asserted
within T21 after the end of the write transaction.
0ns
25ns
50ns
75ns
100ns
125ns
NetChip Technology; NET2272; Slow Mode DMA Write; 8/19/02; DMAWR.TD
DREQ
D0
LD[15:0]
D1
DACK#
IOW# (Optional)
EOT# (Optional)
4.6.2.2 Fast DMA Write Timing
In this mode, DREQ is de-asserted at the beginning of the write transaction. It is then re-asserted within T21 after
the end of the write transaction.
0ns
25ns
50ns
75ns
1
NetChip Technology; NET2272; Fast Mode DMA Write; 8/19/02; DMAWR_FAST.TD
DREQ
LD[15:0]
D0
D1
D2
DACK#
IOW# (Optional)
EOT# (Optional)
4.6.2.3 Burst DMA Write Timing
In this mode, DREQ remains asserted until the DMA transfer completes.
0ns
25ns
50ns
75ns
1
NetChip Technology; NET2272; Burst Mode DMA Write; 09/04/02; DMAWR_BURST.TD
DREQ
LD[15:0]
D0
D1
D2
DACK#
IOW# (Optional)
EOT# (Optional)
______________________________________________________________________________ 28
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
4.6.3 DMA Split Bus Mode
In this mode, the external DMA controller is connected to LD[15:8] of the data bus, while the local CPU is
connected to LD[7:0] of the data bus. The DMA Split Bus Mode bit of the LOCCTL register enables DMA split
Bus Mode.
The split mode DMA transactions are the same as normal DMA transactions, except that DMARD# is used instead
of IOR#, and DMAWR# is used instead of IOW#. While DMA transactions are taking place using LD[15:8], the
local CPU can simultaneously access configuration registers for any endpoint, and can access endpoint buffers not
involved with the DMA.
4.6.4 Terminating DMA Transfers
The EOT signal is used to halt a DMA transfer, and is typically provided by an external DMA controller. It should
be asserted while DACK (and optionally IOR#, IOW#, DMARD#, or DMAWR#) are simultaneously active to
indicate that DMA activity has stopped. Although an EOT signal indicates that DMA has terminated, the USB
transfer (in the case of an IN transaction) is not complete until the last byte has been transferred from the endpoint’s
buffer to the USB. The EOT input resets the NET2272 DMA Request Enable bit of the DMAREQ register. When
EOT is detected, the current endpoint buffer is automatically validated, causing any remaining data in the current
packet to be sent to the host as a short packet. If there is no data in the buffer when the current buffer is validated,
then a zero length packet will be returned in response to the next IN token. The DMA Request Enable bit is also
automatically cleared when the EP_TRANSFER counter reaches zero for IN endpoints or when the local CPU
writes a 0 to the EP_TRANSFER counter.
If the external DMA controller doesn’t provide an EOT signal, the local CPU can terminate the DMA transfer at any
time by resetting the NET2272 DMA Request Enable bit. If the NET2272 DMA Request Enable bit is cleared
during the middle of a DMA cycle (only possible if using DMA split mode), the current cycle will complete before
DMA requests are terminated. The endpoint buffer is not automatically validated when the DMA Request Enable is
cleared. In this case, the CPU needs to explicitly validate the packet by writing a zero to the EP_TRANSFER
register.
______________________________________________________________________________ 29
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
4.6.5 DMA Performance
4.6.5.1 DMA Read; Slow Mode
•
•
•
•
•
•
DREQ to DACK: 5 nsec (depends on DMA controller)
DACK asserted to DREQ de-asserted (T20): 50 nsec
DREQ de-asserted to DREQ asserted (T25): 25 nsec
For an 8-bit bus, the maximum performance is:
1/80 nsec = 12.5 Mbytes/sec
For a 16-bit bus, the maximum performance is:
2/80 nsec = 25 Mbytes/sec
The actual throughput will be reduced if the DMA controller DREQ to DACK delay is longer than 5 nsec.
4.6.5.2 DMA Read; Fast Mode
•
•
•
•
•
•
DREQ to DACK: 5 nsec (depends on DMA controller)
Read Width (T22): 16 nsec
DACK de-asserted to DREQ asserted (T21): 35 nsec
For an 8-bit bus, the maximum performance is:
1/56 nsec = 17.8 Mbytes/sec
For a 16-bit bus, the maximum performance is:
2/56 nsec = 35.7 Mbytes/sec
The actual throughput will be reduced if the DMA controller DREQ to DACK delay is longer than 5 nsec.
4.6.5.3 DMA Read; Burst Mode
•
•
•
DMA Read Cycle time (T17): 35 nsec
For an 8-bit bus, the maximum performance is:
1/35 nsec = 28 Mbytes/sec
For a 16-bit bus, the maximum performance is:
2/35 nsec = 57 Mbytes/sec
4.6.5.4 DMA Write; Slow Mode
•
•
•
•
•
•
DREQ to DACK: 5 nsec (depends on DMA controller)
DACK asserted to DREQ de-asserted (T20): 50 nsec
DREQ de-asserted to DREQ asserted (T25): 25 nsec
For an 8-bit bus, the maximum performance is:
1/80 nsec = 12.5 Mbytes/sec
For a 16-bit bus, the maximum performance is:
2/80 nsec = 25 Mbytes/sec
The actual throughput will be reduced if the DMA controller DREQ to DACK delay is longer than 5 nsec.
4.6.5.5 DMA Write; Fast Mode
•
•
•
•
•
•
DREQ to DACK: 5 nsec (depends on DMA controller)
Write Width (T26): 5 nsec
DACK de-asserted to DREQ asserted (T21): 45 nsec
For an 8-bit bus, the maximum performance is:
1/55 nsec = 18 Mbytes/sec
For a 16-bit bus, the maximum performance is:
2/55 nsec = 36 Mbytes/sec
The actual throughput will be reduced if the DMA controller DREQ to DACK delay is longer than 5 nsec.
______________________________________________________________________________ 30
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
4.6.5.6 DMA Write; Burst Mode
•
•
•
•
Write Width (T26): 5 nsec
Write recovery (T30): 28 nsec
For an 8-bit bus, the maximum performance is:
1/33 nsec = 30 Mbytes/sec
For a 16-bit bus, the maximum performance is:
2/33 nsec = 60 Mbytes/sec
______________________________________________________________________________ 31
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
5 USB Functional Description
5.1
USB Interface
The NET2272 is a USB function device, and as a result is always a slave to the USB host. The bit and packet level
protocols, as well as the electrical interface of the NET2272, conform to USB Specification Version 2.0. The USB
host initiates all USB data transfers to and from the NET2272 USB port. The NET2272 can be configured for up to
3 physical and 30 virtual endpoints, in addition to Endpoint 0. Each endpoint can be an isochronous, bulk or
interrupt type. The configuration registers are used to program the characteristics of each endpoint. The NET2272
operates in either Full speed (12 Mbps) or High speed (480 Mbps) modes.
5.2
USB Protocol
The packet protocol of the USB bus consists of tokens, packets, transactions, and transfers.
5.2.1 Tokens
Tokens are a type of Packet Identifier (PID), and follow the sync byte at the beginning of a token packet. The four
classic types of tokens are OUT, IN, SOF, and SETUP. In high speed mode, the NET2272 also recognizes the
PING token.
5.2.2 Packets
There are four types of packets: start-of-frame (SOF), token, data, and handshake. Each packet begins with a sync
field and a Packet Identifier (PID). The other fields vary depending on the type of packet.
An SOF packet consists of the following fields:
• Sync byte (8-bits)
• Packet Identifier (8-bits)
• Frame Number (11-bits)
• CRC (5-bits)
A token packet consists of the following fields:
• Sync byte (8-bits)
• Packet Identifier (8-bits)
• Address (7-bits)
• Endpoint (4-bits)
• CRC (5-bits)
A data packet consists of the following fields: a token packet always precedes Data packets.
• Sync byte (8-bits)
• Packet Identifier (8-bits)
• Data (n bytes)
• CRC (16-bits)
A handshake packet consists of the following fields:
• Sync byte (8-bits)
• Packet Identifier (8-bits)
______________________________________________________________________________ 32
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
5.2.3 Transaction
A transaction consists of a token packet, optional data packet(s), and a handshake packet.
5.2.4 Transfer
A transfer consists of one or more transactions. Control transfers consist of a setup transaction, optional data
transactions, and a handshake (status) transaction.
5.3
Automatic Retries
5.3.1 Out Transactions
If an error occurs during an OUT transaction, the NET2272 reloads its local side buffer read pointer back to the
beginning of the failed packet. The host then sends another OUT token and re-transmits the packet. Once the
packet has been successfully received by the NET2272, the Packet Received interrupt is set. The NET2272 can
handle any number of back-to-back retries, but the host determines how many times a packet is retried.
5.3.2 In Transactions
If an error occurs during an IN transaction, the NET2272 reloads its USB side buffer read pointer back to the
beginning of the failed packet. The host then sends another IN token and the NET2272 re-transmits the packet.
Once the host has successfully received the packet, the Packet Transmitted interrupt is set.
5.4
Ping Flow Control
When operating in high speed mode, the NET2272 supports the PING protocol for bulk OUT and control endpoints.
This protocol allows the NET2272 to indicate to the host that it can't accept an OUT data packet. The host then
sends PING tokens to query the NET2272. Once the NET2272 can accept a maximum size packet, it returns an
ACK in response to the PING. Now the host sends an OUT token and data packet. The NET2272 returns an ACK
handshake if the packet is accepted, and there is space to receive an additional packet. If it can accept the current
packet, but no others, it returns a NYET handshake to the host. The host then starts sending PING tokens again.
5.5
Packet Sizes
The maximum packet size of an endpoint is determined by the corresponding EP_MAXPKT register. For IN
transactions, the NET2272 will return a maximum size packet to the host if there are at least ‘max packet’ bytes in
the buffer. A packet of size less than the maximum is returned to the host in response to an IN token if the data in
the buffer has been explicitly validated.
The following table shows the allowable maximum packet sizes:
Type of Endpoint
Control
Bulk
Interrupt
Isochronous
Low Speed Mode
(Not Supported)
8
N/A
8
N/A
Full Speed Mode
High Speed Mode
8, 16, 32, 64
8, 16, 32, 64
64 max
1023 max
64
512
1024 max
1024 max
______________________________________________________________________________ 33
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
5.6
NET2272 USB Peripheral Controller
USB Endpoints
The NET2272 supports Control, Isochronous, Bulk, and Interrupt endpoints. All endpoints are unidirectional except
for Control endpoints. Bi-directional bulk, isochronous, or interrupt traffic requires two endpoints.
5.6.1 Control Endpoint - Endpoint 0
The control endpoint, Endpoint 0, is a reserved endpoint. The host uses this endpoint to configure and gain
information about the device, its configurations, interfaces and other endpoints. Control endpoints are bi-directional,
and data delivery is guaranteed.
The host sends 8-byte setup packets to Endpoint 0 to which the device interprets and responds. The NET2272 has a
set of registers dedicated to storing the setup packet, and uses the endpoint 0 packet buffer for Control data. For
Control writes, data flows through the packet buffer from the USB bus to the local bus. For Control reads, data
flows through the packet buffer from the local bus to the USB bus.
When Endpoint 0 detects a setup packet, the NET2272 sets status bits and interrupts the local CPU. The CPU reads
the setup packet from NET2272 registers, and responds based on the contents. The local CPU provides any data
returned to the host, including status and descriptors. Refer to Chapter 9, Standard Device Requests, for a
description of the data that must be returned for each USB request. The host will reject descriptors that have
unexpected values in any of the fields.
5.6.1.1 Control Write Transfer
A successful control write transfer to Control Endpoint 0 consists of the following:
Transaction
Setup
Data (zero, one
or more packets)
Status
Stage
Packet Contents
Setup Token
Data
Status
OUT Token
SETUP PID, address, endpoint, and CRC5
DATA0 PID, 8 data bytes, and CRC16
ACK
OUT PID, address, endpoint, and CRC5
# of
bytes
3
11
1
3
Data (1/0)
Status
IN Token
Data
Status
DATA PID, N data bytes, and CRC16
ACK
IN PID, address, endpoint, and CRC5
DATA1 PID, zero length packet, and CRC16
ACK
N+3
1
3
3
1
Source
Host
Host
NET2272
Host
Host
NET2272
Host
NET2272
Host
During the Setup transaction, the NET2272 stores the data stage packet in its setup registers. The NET2272 returns
an ACK handshake to the host after all 8 bytes have been received. A Setup Packet Interrupt bit is set to notify the
local CPU that a setup packet has been received. The 8-byte data packet is then read and interpreted by the local
CPU. A Setup transaction cannot be stalled or NAKed, but if the data is corrupted, then the NET2272 will not return
an ACK to the host.
During the Data transaction, zero, one or more data packets are written into the Endpoint 0 buffer. For each packet:
• Interrupt bits are set and can interrupt the local CPU
• The local CPU reads the buffer
• The NET2272 returns an ACK if no error has occurred.
For a successful Status transaction, the NET2272 returns a zero length data packet. A NAK or STALL handshake
can be returned if an error occurred.
______________________________________________________________________________ 34
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
5.6.2 Control Write Transfer Details
For control write transfers, the host first sends 8 bytes of setup information. The setup bytes are stored into an 8-byte
register bank that can be accessed by the local CPU. After the eight bytes have been stored into the setup registers,
the Setup Packet Interrupt bit is set. The local CPU then reads the 8-byte setup packet and prepares to respond to
the optional Data transactions. The number of bytes to be transferred in the Data transactions is specified in the
setup packet. When the setup packet is received, the Control Status Phase Handshake bit is automatically set in
anticipation of the control status phase. While this bit is set, the control status phase will be acknowledged with a
NAK, allowing the local CPU to prepare its handshake response (ACK or STALL). Once the Control Status Phase
Handshake bit is cleared and the OUT buffer is empty, the ACK or STALL handshake will be returned to the host.
Waiting for the OUT FIFO to become empty prevents another Control Write from corrupting the current packet data
in the FIFO.
During a control write operation, optional Data transactions can follow the Setup transaction. The Data Out Token
Interrupt bit is set at the beginning of each Data transaction. The bytes corresponding to the Data transaction are
stored into the Endpoint 0 packet buffer. If the buffer fills up and another byte is transferred from the host, the
NET2272 will return a NAK handshake to the host, signaling that the data could not be accepted.
If a packet is not successfully received (NAK or Timeout status), the Data Packet Received Interrupt bit will not be
set, and the data will be automatically flushed from the buffer. The host will re-send the same packet again. This
process is transparent to the local CPU.
If the local CPU has stalled this endpoint by setting the Endpoint Halt bit, the NET2272 will not store any data into
the buffer, and will respond with a STALL acknowledge to the host. There will not be a Status transaction in this
case.
The local CPU can either poll the Data Packet Received Interrupt bit, or enable it as an interrupt, and then read the
packet from the buffer when the interrupt occurs. If the host tries to write more data than was indicated in the setup
packet, then the local CPU should set the Endpoint Halt bit for Endpoint 0. In this case there will not be a status
stage from the host.
After all of the optional Data transaction packets have been received, the host will send an IN token, signifying the
Status transaction. The Control Status Interrupt bit is set after the IN token of the Status transaction has been
received. Until the Control Status Phase Handshake bit is cleared by the local CPU and the OUT buffer is empty,
the NET2272 will respond to the Status transaction with NAKs, indicating that the device is still processing the
setup command. When the Control Status Phase Handshake bit has been cleared by the local CPU and the firmware
has emptied the data form the OUT buffer, the NET2272 will respond with a zero length data packet (transfer OK)
or STALL (device had an error).
______________________________________________________________________________ 35
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
5.6.2.1 Control Read Transfer
A successful control read transfer from Control Endpoint 0 consists of the following:
Transaction
Setup
Data (zero, one, or
more packets)
Status
Stage
Setup Token
Data
Status
IN Token
Packet Contents
SETUP PID, address, endpoint, and CRC5
DATA0 PID, 8 data bytes, and CRC16
ACK
IN PID, address, endpoint, and CRC5
Data (1/0)
DATA PID, N data bytes, and CRC16
Status
OUT Token
Data
Status
ACK
OUT PID, address, endpoint, and CRC5
DATA1 PID, zero length packet, and CRC5
ACK
# of bytes
3
11
1
3
Source
Host
Host
NET2272
Host
N+3
NET2272
1
3
3
1
Host
Host
Host
NET2272
The Setup transaction is processed in the same way as for control write transfers.
During the Data transaction, zero, one or more data packets are read from the Endpoint 0 buffer. For each packet:
• Interrupt bits are set and can interrupt the local CPU
• The local CPU writes data to the buffer
• If there is no data in the buffer, a NAK or zero length packet is returned to the host
• The Host returns an ACK to the NET2272 if no error has occurred.
For a successful Status transaction, the Host sends a zero length data packet, and the NET2272 responds with an
ACK. A NAK or STALL can be returned if an error occurred.
5.6.2.2 Control Read Transfer Details
For control read transfers, the host first sends 8 bytes of setup information. The setup bytes are stored into an 8-byte
register bank that can be accessed from the local CPU. After the eight bytes have been stored into the setup registers,
the Setup Packet Interrupt bit is set. The local CPU then reads the 8-byte setup packet and prepares to respond to
the optional Data transactions. The number of bytes to be transferred in the Data transactions is specified in the
setup packet. When the setup packet is received, the Control Status Phase Handshake bit is automatically set. While
this bit is set, the control status phase will be acknowledged with a NAK, allowing the local CPU to prepare its
handshake response (ACK or STALL). Once the Control Status Phase Handshake bit is cleared, the ACK or
STALL handshake will be returned to the host.
During a control read operation, optional Data transactions can follow the Setup transaction. After the Setup
transaction, the local CPU can start writing the first byte of packet data into the Endpoint 0 buffer in anticipation of
the Data transaction. The Data In Token Interrupt bit is set at the beginning of each Data transaction. If there is
data in the Endpoint 0 buffer, it is returned to the host. If Endpoint 0 has no data to return, it returns either a zero
length packet (signaling that there is no more data available) or a NAK handshake (the data is not available yet).
______________________________________________________________________________ 36
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
Packet Validated
0
X
1
1
Amount of Data in buffer
< Max Packet Size
>= Max Packet Size
empty
>0
Action
NAK to host
Return data to host
Zero length packet to host
Return data to host
After each packet has been sent to the host, the Data Packet Transmitted Interrupt bit is set.
If a packet is not successfully transmitted (Timeout status bit set), the Data Packet Transmitted Interrupt bit will not
be set, and the same packet is sent to the host when another IN token is received. The retry operation is transparent
to the local CPU.
If the host tries to read more data than was requested in the setup packet, the local CPU should set the STALL bit for
the endpoint.
After all of the optional Data transaction packets have been transmitted, the host will send an OUT token, followed
by a zero length data packet, signifying the Status transaction. The Control Status Interrupt bit is set after the OUT
token of the Status transaction has been received. Until the Control Status Phase Handshake bit is cleared by the
local CPU, the NET2272 will respond to the Status transaction with NAKs, indicating that the device is still
processing the command specified by the Setup transaction. When the Control Status Phase Handshake bit has been
cleared by the local CPU, the NET2272 will respond with an ACK (transfer OK) or STALL (Endpoint 0 is stalled).
5.6.3 Isochronous Endpoints
Isochronous endpoints are used for the transfer of time critical data. Isochronous transfers do not support any
handshaking or error checking protocol, and are guaranteed a certain amount of bandwidth during each frame. The
Serial Interface Engine in the NET2272 ignores CRC and bit stuffing errors during isochronous transfers, but sets
the handshaking status bits in the EP_STAT registers the same as for non-isochronous packets so that the local CPU
can detect errors. Isochronous endpoints are unidirectional, with the direction defined by the endpoint configuration
registers.
For isochronous endpoints, the packet buffer size must be equal to or greater than the maximum packet size. The
maximum packet size for an isochronous endpoint ranges from 1 to 1024 bytes.
For an Isochronous OUT endpoint, the local CPU or DMA can read data from the endpoint buffer after an entire
packet has been received. If the endpoint buffer is the same size as the maximum packet size, then the ISO
bandwidth must be set such that the buffer can be emptied before the next ISO packet arrives.
For an Isochronous IN endpoint, the local CPU or DMA can write data to one endpoint buffer at the same time that
data is being transmitted to the USB from the other endpoint buffer (double-buffered mode only).
______________________________________________________________________________ 37
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
5.6.3.1 Isochronous Out Transactions
Isochronous Out endpoints are used to transfer data from a USB host to the NET2272 local bus. An Isochronous
OUT transaction consists of the following:
Stage
OUT Token
Data
Packet Contents
OUT PID, address, endpoint, and CRC5
DATA0 PID, N data bytes, and CRC16
Number of bytes
3
N+3
Source
Host
Host
The USB host initiates an Isochronous OUT transaction by sending an OUT token to an Isochronous OUT endpoint.
The Data OUT Token Interrupt bit is set when the OUT token is recognized. The bytes corresponding to the Data
stage are stored into the endpoint’s buffer. Isochronous transactions are not retried, so if the buffer is full when a
packet is transferred from the host (or the NAK OUT Packets bit is set), the packet is discarded and the FIFO
Overflow status bit is set. No handshake packets are returned to the host, but the USB OUT ACK Sent, and Timeout
status bits are still set to indicate the status of the transaction. If a CRC error is detected, the packet is accepted and
the Timeout status bit is set. After every data packet is received, the local CPU should sample these status bits to
determine if the NET2272 successfully received the packet.
By definition, isochronous endpoints do not utilize handshaking with the host. Since there is no way to return a stall
handshake from an isochronous endpoint to the host, data that is sent to a stalled isochronous endpoint will be
received normally. The Maximum Packet Size must be less than or equal to the buffer size.
The local CPU must wait for the Data Packet Received Interrupt bit to be set before reading the data from the
buffer. If the endpoint is programmed for a single-buffering, then the host should be programmed to allow the local
CPU enough time to unload the buffer before the next packet is sent. If the endpoint is programmed for doublebuffering, then the local side can unload one packet while the next one is being received.
5.6.3.2 High Bandwidth Isochronous OUT Transactions
The host sends high-bandwidth OUT PID sequences for each microframe depending on the Additional Transaction
Opportunities field in the Endpoint Descriptor as follows:
Additional
Opportunities
0
1
2
PID Sequence
DATA0 (normal ISO)
MDATA, DATA1 (one extra transaction)
MDATA, MDATA, DATA2 (two extra transactions)
The NET2272 accepts data (unless the endpoint buffer is full), and records the PID in the High-Bandwidth OUT
Transaction PID field of the Endpoint High Bandwidth register. This allows firmware to track PIDs as they arrive
and determine if the data sequence is complete.
High-Bandwidth
OUT Transaction
PID field
PID Received
00
01
10
11
DATA0
DATA1
DATA2
MDATA
______________________________________________________________________________ 38
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
5.6.3.3 Isochronous In Transactions
Isochronous IN endpoints are used to transfer data from the NET2272 local bus to a USB host. An isochronous IN
transaction consists of the following:
Stage
IN Token
Data
Packet Contents
IN PID, address, endpoint, and CRC5
DATA0 PID, N data bytes, and CRC16
Number of bytes
3
N+3
Source
Host
NET2272
The USB host initiates an Isochronous IN transaction by sending an IN token to an Isochronous IN endpoint. The
Data IN Token Interrupt bit is set when the IN token is recognized. If there is data in the endpoint’s buffer, it is
returned to the host. If the endpoint has no data to return, a zero length packet is returned to the host. The NET2272
responds to the IN token according to the following table.
Packet Validated
0
Amount of Data in Buffer
< Max Packet Size
X
1
1
>= Max Packet Size
empty
>0
Action
Zero length packet to host; USB
IN NAK Sent status bit set
Return data to host.
Zero length packet to host
Return data to host
After the packet has been sent to the host, the Data Packet Transmitted Interrupt bit is set. If an IN token arrives
and there is no valid packet in the endpoint buffer, the NET2272 returns a zero-length packet, and the FIFO
Underflow status bit is set. No handshake packets are returned to the host, but the USB IN ACK Sent, and Timeout
status bits are still set to indicate the status of the transaction. After every data packet is transmitted, the local CPU
should sample these status bits to determine if the packet was successfully transmitted to the host.
By definition, isochronous endpoints do not utilize handshaking with the host. Since there is no way to return a stall
handshake from an isochronous endpoint to the host, data that is requested from a stalled isochronous endpoint will
be transmitted normally.
5.6.3.4 High Bandwidth Isochronous IN Transactions
A USB device is required to send ISO PID sequences for each microframe according to the Additional Transaction
Opportunities field in the Endpoint Descriptor and the EP_n_HS_MAXPKT register as follows:
Additional
Opportunities
0
1
2
PID Sequence
DATA0 (normal ISO)
DATA1, DATA0 (one extra transaction)
DATA2, DATA1, DATA0 (two extra transactions)
When the first IN token of a microframe arrives, the NET2272 copies the Additional Opportunities field from the
EP_n_HS_MAXPKT register to determine the initial PID. On each succeeding IN token of the microframe, the
PID advances to the next token.
______________________________________________________________________________ 39
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
5.6.4 Bulk Endpoints
Bulk endpoints are used for guaranteed error-free delivery of large amounts of data between a host and device. Bulk
endpoints are unidirectional, with the direction defined by the endpoint configuration registers.
5.6.4.1 Bulk Out Transactions
Bulk Out endpoints are used to transfer data from a USB host to the NET2272 local bus. A bulk OUT transaction to
a Bulk Out endpoint consists of the following:
Stage
OUT Token
Data (1/0)
Status
Packet Contents
OUT PID, address, endpoint, and CRC5
DATA PID, N data bytes, and CRC16
ACK, NAK, or STALL
Number of bytes
3
N+3
1
Source
Host
Host
NET2272
The USB host initiates a Bulk OUT transaction by sending an OUT token to a Bulk OUT endpoint. The Data OUT
Token Interrupt bit is set when the OUT token is recognized. The bytes corresponding to the Data stage are stored
into the endpoint’s buffer. If the buffer is full when another packet is transferred from the host, the packet will be
discarded and the USB OUT NAK Sent status bit will be set. At the completion of the packet, a NAK handshake will
be returned to the host, indicating that the packet could not be accepted.
All USB data passes through the endpoint’s buffer to the local bus. The CPU waits until the Data Packet Received
Interrupt occurs before reading the data from the buffer.
If a packet is not successfully received (USB OUT NAK Sent or Timeout status bits set), the Data Packet Received
Interrupt bit will not be set, and the data will be automatically flushed from the buffer. The host will re-send the
same packet again. This process is transparent to the local CPU.
If the local CPU has stalled this endpoint by setting the Endpoint Halt bit, the NET2272 will not store any data into
the buffer, and will respond with a STALL handshake to the host.
______________________________________________________________________________ 40
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
5.6.4.2 Bulk In Endpoints
Bulk IN Endpoints are used to transfer data from the NET2272 local bus to a USB host. A bulk IN transaction from
a Bulk IN Endpoint consists of the following:
Stage
IN Token
Data (1/0)
Status
Packet Contents
IN PID, address, endpoint, and CRC5
DATA PID, N data bytes, and CRC16, or NAK or STALL
ACK
Number of bytes
3
N+3
1
Source
Host
NET2272
Host
The USB host initiates a Bulk IN transaction by sending an IN token to a Bulk IN endpoint. The Data IN Token
Interrupt bit is set when the IN token is recognized. If there is validated data in the endpoint’s buffer, it is returned
to the host. If the endpoint has no data to return, it returns either a zero length packet (signaling that there is no
more data available) or a NAK handshake (the data is not available yet).
Packet Validated
0
X
1
1
Amount of Data in Buffer
< Max Packet Size
>= Max Packet Size
empty
>0
Action
NAK to host
Return data to host
Zero length packet to host
Return data to host
After the packet has been sent to the host, the Data Packet Transmitted Interrupt bit is set.
If a packet is not successfully transmitted (Timeout status bit set), the Data Packet Transmitted Interrupt bit will not
be set, and the same packet is sent to the host when another IN token is received. The retry operation is transparent
to the local CPU.
If the local CPU has stalled this endpoint by setting the Endpoint Halt bit, the NET2272 will respond to the IN token
with a STALL handshake to the host.
______________________________________________________________________________ 41
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
5.6.5 Interrupt Endpoints
Interrupt endpoints are used for sending or receiving small amounts of data to the host with a bounded service
period.
5.6.5.1 Interrupt Out Transactions
Interrupt Out endpoints are used to transfer data from a USB host to the NET2272 local bus. An interrupt OUT
transaction to an Interrupt OUT endpoint consists of the following:
Stage
OUT Token
Data (1/0)
Status
Packet Contents
OUT PID, address, endpoint, and CRC5
DATA PID, N data bytes, and CRC16
ACK, NAK, or STALL
Number of bytes
3
N+3
1
Source
Host
Host
NET2272
The behavior of an Interrupt OUT endpoint is almost the same as a Bulk OUT endpoint, except for the toggle bit. If
the Interrupt Mode bit is cleared, the toggle bit of the Interrupt OUT endpoint is initialized to 0 (DATA0 PID), and
behaves the same as a Bulk OUT endpoint. If the Interrupt Mode bit is set, the toggle bit of the Interrupt OUT
endpoint changes after each data packet is received from the host, without regard to the Status stage. Note that the
PING protocol is not allowed for Interrupt OUT endpoints, as per the USB Specification.
5.6.5.2 Interrupt In Endpoints
An Interrupt IN endpoint is polled at a rate which is specified in the endpoint descriptor. An interrupt transaction
from an Interrupt IN endpoint consists of the following:
Stage
IN Token
Data (1/0)
Status
Packet Contents
IN PID, address, endpoint, and CRC5
DATA PID, N data bytes, and CRC16
ACK
Number of bytes
3
N+3
1
Source
Host
NET2272
Host
The behavior of an Interrupt IN endpoint is the same as a Bulk IN endpoint, except for the toggle bit. If the
Interrupt Mode bit is cleared, the toggle bit of the Interrupt IN endpoint is initialized to 0 (DATA0 PID), and
behaves the same as a Bulk IN endpoint. An interrupt endpoint may be used to communicate rate feedback
information for certain types of isochronous functions. To support this mode, the Interrupt Mode bit is set, and the
toggle bit of the Interrupt IN endpoint changes after each data packet is sent to the host, without regard to the Status
stage.
5.6.5.3 High Bandwidth INTERRUPT Endpoints
From the USB device point of view, high-bandwidth INTERRUPT endpoints are the same as BULK endpoints,
except that the MAXPKT can be any value from 1 to 1024. Normal INTERRUPT endpoints in full-speed mode can
set MAXPKT from 1 to 64.
______________________________________________________________________________ 42
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
5.7
NET2272 USB Peripheral Controller
NetChip Virtual Endpoints
5.7.1 Overview:
The Net2272 features NetChip Virtual Endpoint hardware support which enables firmware to implement any
number of USB device endpoints up to the maximum of 15 per direction, excluding endpoint 0 (see the USB 2.0
Specification sections 8.3.2.2 and 9.6.6). Hardware support for endpoint virtualization consists of the Virtual
Endpoint registers (VIRTOUT0, VIRTOUT1, VIRTIN0, and VIRTIN1) and the Virtual Endpoint Interrupt.
In this section, "logical endpoint" refers to the endpoint number from the point of view of the host (embedded in IN,
OUT, and SETUP tokens), "physical endpoint" refers to the Net2272 hardware endpoint (0, A, B, or C), and
"unassigned endpoint" refers to a logical endpoint number that is not currently assigned (via the Endpoint Address
field in the EP_CFG register) to a physical endpoint.
If the Virtual Endpoint Enable bit of the USBCLT1 register is low (default), the Net2272 responds to a host request
to an unassigned endpoint with a timeout. The host considers a timeout response to be a fatal error. The host retries
a transaction with a fatal error, but after a fixed number of retries, the host shuts down the pipe (endpoint).
If Virtual Endpoint Enable bit is high, the Net2272 responds to all requests on unassigned endpoints with a NAK.
This causes the host to retry the request until an ACK is returned.
In addition to NAKing, the Net2272 sets the bit in the Virtual Interrupt register that corresponds to the requesting
logical endpoint number. For example, if the host requests an IN on endpoint 3 when none of the Net2272 physical
endpoints is assigned to address 3 with direction IN, bit 3 of the VIRTIN0 register is set (and the Net2272 NAKs
the IN request).
While any of the Virtual Endpoint register bits are set, the Virtual Endpoint Interrupt status bit will be set. If this
interrupt is enabled, firmware is notified that the host has tried to access an unassigned endpoint. Firmware can then
re-assign one of the physical endpoints to the new logical endpoint so the data transaction can proceed.
Virtual Endpoint participation is completely flexible: all physical endpoints (excluding endpoint 0) may participate
in Virtual Endpoint re-assignment, or some physical endpoints can be dedicated to specific high-usage logical
endpoints.
5.7.2 Endpoint Virtualization
Virtualization relies on the ability of the firmware to capture, preserve, and restore the complete endpoint state as it
switches the available physical endpoint resources between a larger number of logical endpoints (similar to a CPU
context switch). NetChip Virtual Endpoint hardware support makes all the endpoint state information available to
the firmware.
When re-assigning endpoints, firmware must take care that USB traffic is not disturbed. Specifically, an endpoint
should not be reprogrammed or flushed while the endpoint is enabled. NetChip Virtual Endpoint hardware support
includes logic to prevent an endpoint's enable state from changing while a USB transaction to the endpoint is in
progress, so firmware should first disable the endpoint, and then check that the enable has succeeded (there may be a
delay while a pending USB transaction completes).
______________________________________________________________________________ 43
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
Before re-assigning an IN endpoint, firmware should:
1. Stop loading data into the endpoint
2a. Wait until there are no buffers are waiting to be sent to the host (buffer states are available in the
EP_BUFF_STATE register). Note that because of the USB-inherent problem discussed in section
8.5.3.3 of the USB 2.0 Specification, waiting for the endpoint to empty can potentially lead to deadlock.
3a. Write 0 to the Endpoint Enable bit in the EP_CFG register.
4a. Check that the Endpoint Enable bit is clear.
OR
2b. Write 0 to the Endpoint Enable bit in the EP_CFG register.
3b. Check that the Endpoint Enable bit is clear.
4b. Read out and store any packets still loaded in the endpoint buffers. Reading is accomplished by
clearing the Endpoint Direction bit in the EP_CFG register so that buffer data is available to EP_DATA,
and the count is available in EP_AVAIL. Note that zero-length packets should also be detected, read
out, and stored. Zero-length packets can be detected from the EP_BUFF_STATE register.
5. Save the endpoint registers: EP_CFG, EP_IRQENB, EP_TRANSFER, EP_RSPSET, and
EP_MAXPKT.
6. Re-assign the endpoint.
Before re-assigning an OUT endpoint:
1. Write 0 to the Endpoint Enable bit in the EP_CFG register.
2. Check that the Endpoint Enable bit is clear.
3. If there is any data available in the endpoint buffers, read it all out. Note that the host may send a packet
after firmware clears Endpoint Enable but before the endpoint is disabled.
4. Save the endpoint registers: EP_CFG, EP_IRQENB, EP_TRANSFER, EP_RSPSET, and
EP_MAXPKT.
5. Re-assign the endpoint.
Re-assigning a physical endpoint consists of programming the direction, type, and logical endpoint number and
setting Endpoint Enable in EP_CFG (these can all be done in a single register write operation), and loading
EP_IRQENB, EP_TRANSFER, EP_RSPSET, and EP_MAXPKT. The endpoint should also be flushed before
loading any data or enabling it.
Restoring EP_RSPSET/CLR requires two register writes, one to EP_RSPCLR with the logical NOT of the saved
EP_RSPSET value, and a second write to EP_RSPSET with the saved EP_RSPSET value. Note that clearing the
endpoint HALT bit also clears the endpoint toggle bit, so the write to EP_RSPCLR should occur first, followed by
the write to EP_RSPSET.
When restoring an IN endpoint with stored buffer data (method 2b-4b above), care should be take to restore
EP_TRANSFER correctly. Either EP_TRANSFER can be loaded with the stored EP_TRANSFER value plus the
count of stored data before the stored data is loaded, or the stored data can be loaded first (and packets validated by
writing 0 to EP_TRANSFER) followed by restoring EP_TRANSFER to the stored value.
5.7.3 Efficiency Considerations:
Depending on the number of virtual endpoints and the host-controller requirements, firmware may need to prioritize
virtual endpoint re-assignment. For example, a simple scheme of scheduling the lowest virtual endpoint request
each time might end up starving higher logical endpoint addresses. A "round-robin" priority is one method to ensure
at least some data travel on all endpoints.
Note that INTERRUPT endpoints may require special care because the polling interval between accesses can be
very long. It is not efficient to detect the endpoint access on an INTERRUPT endpoint (which was NAKed), switch
to that endpoint, and then detect and switch to a different endpoint before the next INTERRUPT polling interval
arrives. Once possible solution is to “lock down” the physical endpoint (prevent further endpoint switching) until a
minimum number of packets have passed through the endpoint.
______________________________________________________________________________ 44
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
5.7.4 Deadlock Considerations:
Usually, the USB host-controller retries NAKed BULK transactions in a "round-robin" priority, so deadlocks will
not normally occur. However, it may be possible that some host drivers may be susceptible to deadlocks. Specific
device and host driver implementations should be evaluated specifically for deadlock exposure.
For example, step 2a of re-assigning an IN endpoint (above) requires firmware to wait until the physical endpoint is
empty. If the host is not requesting data on the (old) logical endpoint, but is instead waiting for a transaction on the
new logical endpoint (the logical endpoint firmware is trying to switch to, but is prevented because the physical
endpoint is not empty), deadlock occurs.
This particular deadlock can be broken by flushing the IN endpoint if the device is prepared to reload the packet(s),
or if the data can be discarded. Alternatively, the deadlock can be avoided entirely by not loading any data into the
IN logical endpoint until the host has sent an IN token request, or by using method 2b-4b instead.
Another potential source of deadlock is the USB-inherent problem discussed in section 8.5.3.3 of the USB 2.0
Specification. In this situation, the endpoint is not able to flush the final packet of a transfer because it does not
know that the host has received it correctly, and the host may not send another IN on the same endpoint for an
indeterminate time.
5.7.5 Buffer Control
The Net2272 buffers can be read and written from the local bus. This feature can be used for both chip diagnostics
(power-on tests) and during Virtual Endpoint context switching.
When the Endpoint Direction bit of an endpoint (bit 4 of EP_CFG) is set, the endpoint in an IN endpoint and
EP_DATA is a write-only FIFO-style register. After data is loaded into the endpoint, the packet can be validated by
writing 0 to EP_TRANSFER (as a convenience, if the upper two bytes of EP_TRANSFER are already 0, writing 0
to EP_TRANSFER0 validates the packet with a single register write).
After a packet has been validated (or both if the endpoint is configured to be double-buffered), the Endpoint
Direction bit can be switched to OUT (by clearing bit 4 of EP_CFG) and the buffer data can be read out.
EP_AVAIL indicates the number of bytes available in the buffer.
Zero-length packets behave the same as OUT zero-length packets sent by the host, and they are similarly flushed by
a dummy read from EP_DATA. The presence of a zero-length packet is indicated by Local OUT ZLP (bit 6 of
EP_STAT1) or by the buffer states in EP_BUFF_STATES.
Note that data is only available for reading on the OUT EP_DATA register after the packet has been validated while
the endpoint is configured for IN. Data written but not validated is lost when the direction is switched to OUT.
Note also that the endpoint should be disabled before switching directions, and that the disable operation should be
checked (by reading back bit 7 of EP_CFG: Endpoint Enable). This ensures that the USB host does not read the IN
packet before local firmware reads it out.
EP_DATA buffers can be read or written while the endpoint is disabled.
5.7.6 Summary
NetChip’s Virtual Endpoint hardware support allows a USB device to utilize the full potential of USB endpoints by
providing the capability to expose any number of endpoints to the USB host. Firmware can track and assign the
available physical endpoints to the dynamically required logical endpoints with full flexibility. Any number of
endpoints required by any host driver (including USB Class Drivers) can be supported.
______________________________________________________________________________ 45
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
5.8
NET2272 USB Peripheral Controller
Packet Buffers
The NET2272 contains one 3-Kbyte bank of memory that is allocated to the endpoint packet buffers. The
configuration of the endpoint A and B buffers is selected by the Buffer Configuration field of the LOCCTL
configuration register. Available configurations for endpoints A and B are:
• 512 bytes, double-buffered (total of 1K bytes)
• 1024 bytes, single-buffered
• 1024 bytes double-buffered
The total size of all of the endpoint A and B buffers cannot exceed 2 Kbytes. Endpoint C has a 1K byte buffer,
configured as two 512-byte buffers, and endpoint 0 has a 128 byte buffer, configured as two 64-byte buffers. Data is
stored in the buffers in 32-bit words, so each entry contains between 1 and 4 bytes.
If a write to a full buffer is detected, the data is ignored. If a read from an empty buffer is detected, undefined data
is presented on the data bus.
5.8.1 IN Endpoint Buffers
IN packet data is written by the local CPU or DMA into one of the IN endpoint buffers. Once the buffer data has
been validated, it is returned to the USB host in response to an IN token. The NET2272 will not send more than
EP_MAXPKT bytes per packet. Once a packet has been written into a double-buffered buffer and validated, the
local CPU can continue loading data for the next packet. The NET2272 will automatically divide the data flow into
individual packets with a maximum size determined by the associated EP_MAXPKT register. This allows USB
transactions to overlap with loading of data from the local bus.
If the buffer data hasn’t been validated, the NET2272 responds to an IN token with a NAK handshake. There are
several methods for validating the data in the IN buffer:
• For large amounts of data, the local bus controller can write data to the buffer as long as there is space
available. When there are at least EP_MAXPKT bytes in the buffer, the NET2272 will respond to an IN
token with a packet of data. If the entire data transfer is a multiple of EP_MAXPKT bytes, then nothing
else needs to be done to validate the buffer data. If a zero length packet needs to be sent to the host, the
local CPU can write a zero to the EP_TRANSFER register without writing any additional data to the
buffer.
• For moderate amounts of data (between EP_MAXPKT and 16 Mbytes), a counter (EP_TRANSFER) is
used. This counter is initialized to the total transfer byte count before any data is written to the buffer. The
counter is decremented as data is written to the buffer. When the counter reaches zero, the remaining data
in the buffer is validated. If 16-bit transfers are being utilized on the local bus, excess bytes in the last word
are automatically ignored. If the last packet of a transfer has EP_MAXPKT bytes, then the NET2272 will
respond to the next IN token with a zero length packet.
• For small amounts of data (character oriented applications), the data is first written to the buffer. Then a
zero is written to the EP_TRANSFER register, thus causing the data to be validated.
• For a DMA write terminated with an EOT, the buffer data is validated if the DMA Buffer Valid bit in the
DMAREQ register is set. This causes a short or zero-length packet to be transmitted in response to the
next IN token.
Up to 2 short (less than EP_MAXPKT bytes) packets can be stored in a double-buffered packet buffer.
______________________________________________________________________________ 46
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
5.8.1.1 16-bit Post-Validation
Post-validation is the technique in which data is written to the buffer before it is validated. The following steps must
be followed to post-validate an odd length packet, size 2n+1, when operating in 16-bit mode:
• Write ‘2n’ bytes using ‘n’ 16-bit transactions to the endpoint buffer via EP_DATA.
• Change to an 8-bit bus by clearing the Data Width bit in the LOCCTL register.
• Write the last byte to the endpoint buffer via EP_DATA.
• Post-validate the buffer by writing 0 to EP_TRANSFER0.
• Change back to a 16-bit bus by setting the Data Width bit in the LOCCTL register.
5.8.2 OUT Endpoint Buffers
When receiving data, the NET2272 will NAK the host (indicating that it cannot accept the data) if either the buffer
runs out of room, or if both the NAK OUT Packets Mode bit and the NAK OUT Packets bits are set. If the packets
received are of maximum size, then additional packets can be received independently of the NAK OUT Packets
Mode bit. This bit will only cause additional OUT packets to be NAKed if the last packet received was a short
packet.
If NAK OUT Packets Mode is true (blocking mode), USB OUT transfers can overlap with the local CPU unloading
the data using the following sequence:
•
•
•
Local CPU responds to the Data Packet Received Interrupt and reads the EP_AVAIL register so it knows how
many bytes are in the current packet.
Local CPU clears the Data Packet Received Interrupt and the NAK OUT Packets bit, allowing the next packet
to be received.
Now the local CPU can unload data from the buffer while the next USB OUT transaction is occurring.
If NAK OUT Packets Mode is false (non-blocking mode), the NET2272 will accept packets as long as there is room
for the complete packet in the next available buffer. Note that there are no indications of packet boundaries when
there are multiple packets in the buffers in a double-buffered configuration.
______________________________________________________________________________ 47
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
5.9
NET2272 USB Peripheral Controller
USB Test Modes
The Force Full Speed and Force High Speed bits of the XCVRDIAG register can be used to force the NET2272
into full and high speed modes, respectively. These forcing bits must not be used in normal operation; they are
for testing purposed only. In normal operation, the NET2272 automatically performs USB 2.0 Chirp Protocol
negotiation with the host to determine the correct operating speed.
USB 2.0 Test Mode support is provided via the Test Mode Select field of the USBTEST register. These bits select
the appropriate USB Test Mode settings (see section 9.4.9 in the USB Specification Revision 2.0 for more details).
Normally, the host sends a SET_FEATURE request with the Test Selector in the upper byte of wIndex. The Test
Selector can be copied directly into the NET2272 USBTEST register to select the correct test mode.
Note that USB Test Mode settings only have an effect if the NET2272 is in high-speed mode. Also, if the NET2272
is in high-speed mode, and the Test Mode Select field is set to non-zero, the NET2272 is prevented from switching
out of high-speed mode. Normal USB Suspend and Reset, as well as the Force Full Speed and Force High Speed
bits, are ignored for test purposes.
Note also that the NET2272 can be forced into high-speed mode (using the Force High Speed bit) even if the
NET2272 is not connected to a host controller. After selecting the high-speed mode, USB Test Modes can be
selected.
Most USB Test Modes require no further support from the NET2272 firmware. However, the Test_Packet (0x04)
Test Mode Selector requires a specific packet to be returned by the device. The NET2272 will respond correctly by:
1. Set Test Mode Select to 0x04
2. Flush endpoint 0
3. Load the following 53 (0x35) byte packet into endpoint 0:
00 00 00 00 00 00 00 00 - 00 AA AA AA AA AA AA AA AA EE EE EE EE EE EE EE
EE FE FF FF FF FF FF FF FF FF FF FF FF 7F BF DF - EF F7 FB FD FC 7E BF DF EF
F7 FB FD 7E
You may validate the packet with your normal validation method, either pre-validating by writing 0x35 into
EP_TRANSFER[EP0] before loading the bytes, or by writing 0 to EP_TRANSFER[EP0] after loading the bytes.
______________________________________________________________________________ 48
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
6 Interrupt and Status Register Operation
6.1
Interrupt Status Registers (IRQSTAT0, IRQSTAT1)
Bits 3:0 of the IRQSTAT0 register indicate whether one of the endpoints 0, A-C has an interrupt pending. These
bits cannot be written, and can cause a local interrupt if the corresponding interrupt enable bits are set in the
IRQENB0 register. Bit 7 is automatically set when a start-of-frame (SOF) token is received, and is cleared by
writing a 1. This bit can cause a local interrupt if the corresponding interrupt enable bit is set in the IRQENB0
register. Note that the interrupt bits can be set without the corresponding interrupt enable bit being set. This allows
the local CPU to operate in a polled, as well as an interrupt driven environment.
Bits 6:5 of IRQSTAT0 and bits 7:4 and 2:1 of IRQSTAT1 are set when a particular event occurs in the NET2272,
and are cleared by writing a 1 to the corresponding bit. These bits can cause a local interrupt if the corresponding
interrupt enable bits are set in the IRQENB0 and IRQENB1 registers.
Bit 3 of IRQSTAT1 is set when there is a suspend request from the host, but it typically not enabled to generate an
interrupt. Writing a 1 clears this bit and causes the 2272 to enter the suspend state.
6.2
Endpoint Response Registers (EPRSP_CLR, EPRSP_SET)
Each endpoint has a pair of Endpoint Response Registers. The bits in these registers determine how the NET2272
will respond to various situations during a USB transaction. Writing a 1 to any of the bits in the EP_RSPCLR
register will clear the corresponding bits. Writing a 1 to any of the bits in the EP_RSPSET register will set the
corresponding bits. Reading either of the registers returns the current state of the bits.
6.3
Endpoint Status Register (EP_STAT0, EP_STAT1)
Each endpoint has a pair of Endpoint Status Registers. Each of the bits of these registers is set when a particular
endpoint event occurs, and is cleared by writing a 1 to the corresponding bit. A local interrupt can be generated if
the corresponding interrupt enable bits are set in the EP_IRQENB registers. Reading the EP_STAT registers
returns the current state of the bits.
______________________________________________________________________________ 49
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
7 Power Management
7.1
Suspend Mode
When there is a three-millisecond period of inactivity on the USB, the USB specification requires a device to enter
into a low-power suspended state. A low power device may not draw more than 500 µA, and a high-power device
may not draw more than 2.5 mA while in this state. This requirement only applies to bus-powered devices. To
facilitate this, the NET2272 provides a Suspend Request Change Interrupt bit and a Suspend Request Interrupt bit.
Additionally, the NET2272 allows local bus hardware to initiate a “device remote wake-up” to the USB.
7.1.1 The Suspend Sequence
The typical sequence of a suspend operation is as follows:
• During device configuration, the local CPU enables the Suspend Request Change Interrupt bit to generate a
local interrupt.
• When the USB is idle for three milliseconds, the NET2272 sets the Suspend Request Change Interrupt bit,
generating an interrupt to the local CPU. This interrupt can also occur if the NET2272 is not connected to a
host, and the USB data lines are pulled to the idle state (DP high, DM low), or if the VBUS input is low.
• The local CPU accepts this interrupt by clearing the Suspend Request Change Interrupt bit, and performs the
tasks required to ensure that no more than 500 µA of current is drawn from the USB power bus.
• The local CPU writes a 1 to the Suspend Request Interrupt bit to initiate the suspend.
• The LCLKO output continues to operate for 500 µsec before the NET2272 enters the suspend state. This
allows time for a local CPU that uses LCLKO to power down.
• A device remote wakeup event will not be recognized during the 500 µsec suspend delay period.
In suspend mode, the NET2272’s oscillator shuts down, and most output pins are tri-stated to conserve power (see
section 3, Pin Description). Note that input pins to the NET2272 should not be allowed to float during suspend
mode. The NET2272 will leave suspend mode by detecting a host initiated wake-up or by a device remote wake-up.
If a device is self-powered, it may ignore the USB suspend request and never write a 1 to the Suspend Request
Interrupt bit.
______________________________________________________________________________ 50
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
7.1.2 Host-Initiated Wake-Up
The host may wake up the NET2272 by driving any non-idle state on the USB. The NET2272 will detect the host’s
wake-up request, and re-starts its internal oscillator. The host initiated wake-up is only recognized if the VBUS
input pin is high, and the USB Detect Enable and USB Root Port Wakeup Enable bits in the USBCTL0 register are
set.
7.1.3 Device-Remote Wake-Up
The device hardware signals a device remote wake-up by driving the CS# input pin low. If the I/O Wakeup Enable
bit in the USBCTL0 register is set, the NET2272 re-starts its local oscillator. Two milliseconds after the CS# pin is
asserted, the local CPU must write to the Generate Resume bit of the USBCTL1 register. This will cause a 10-ms
wake-up signal to be sent to the USB host.
7.1.4 Resume Interrupt
When the NET2272 begins either a Device-Remote Wake-Up or Host-Initiated Wake-Up, it may be programmed to
generate a resume interrupt. The Resume Interrupt bit of the IRQSTAT1 register is set when a resume is detected,
and can be enabled to generate an interrupt with the Resume Interrupt Enable bit.
7.2
NET2272 Power Configuration
The USB specification defines both bus-powered and self-powered devices. A bus-powered device is a peripheral
that derives all of its power from the upstream USB connector, while a self-powered device has an external power
supply.
The most significant consideration when deciding whether to build a bus-powered or a self-powered device is power
consumption. The USB specification dictates the following requirements for maximum current draw:
• A device not configured by the host can draw only 100 mA from the USB power pins.
• A device may not draw more than 500 mA from the USB connector’s power pins.
• In suspend mode, the device may not draw more than 500 µA (or 2.5 mA for a high-power device)
from the USB connector’s power pins
If these power considerations can be met without the use of an external power supply, the device can be buspowered; otherwise a self-powered design should be implemented.
7.2.1 Self-Powered Device
Generally, a device with higher power requirements will be self-powered. In a self-powered device, the NET2272
VDD pins are powered by the local power supply. This allows the local bus to continue accessing the NET2272, even
when the device is not connected to the USB bus. The USB connector’s power pin is connected directly to the
NET2272 VBUS pin, and is only used to detect whether it is connected to a USB host.
While the device is connected to the USB, the NET2272 will automatically request suspend mode when appropriate.
The NET2272 should not be powered-down when its local bus is still connected to a powered-up device. There are
ESD protection circuits in the NET2272 that will short VDD pins to ground. If the VDD pins are not powered, they
will sink too much current from the board.
7.2.2 Low-Power Modes
7.2.2.1 USB Suspend (Unplugged from USB)
The NET2272 may draw a small amount of power when disconnected from the USB. Disconnecting from the USB
can be accomplished in two different ways:
• Un-plug the USB cable.
• Clear the USB Detect Enable bit in the USBCTL0 register.
______________________________________________________________________________ 51
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
In power-sensitive applications, the local CPU can force the NET2272 to enter low-power suspend mode when
disconnected from the USB by writing a 1 to the Suspend Request Interrupt bit. The NET2272 will automatically
wake-up when the peripheral is re-connected (cable plugged in and USB Detect Enable bit set) to the USB. Do not
force suspend mode unless the peripheral is disconnected from the USB. When the NET2272 is connected to the
USB, it is a violation of the USB specification to enter the suspend state unless the upstream port has been idle for
at least 3 milliseconds.
This is the preferred method of suspending the NET2272, since a USB re-connection will automatically cause the
NET2272 to wake-up and set the Resume Interrupt bit.
7.2.2.2 Power-On Standby
The local CPU can prevent the NET2272 from starting its oscillator on power-up by driving a LOW into the CS#
pin while RESET# is asserted (LOW). In this state the NET2272 requires only a small quiescent standby current.
When the peripheral wishes to start the oscillator, it releases the CS# pin and continues to assert RESET# for a
minimum of 2 milliseconds. Note that while the oscillator is stopped, the NET2272 cannot respond to USB
requests, so the oscillator must be allowed to start when the peripheral detects a USB connection event. The local
CPU is responsible for detecting the connection, and ending the standby condition.
This standby technique is appropriate when the device’s power budget does not allow the NET2272 to be active
long enough to shut it down by setting the Suspend Request Interrupt bit.
______________________________________________________________________________ 52
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
8 Configuration Registers
8.1
Register Description
The NET2272 occupies a 32-byte address space that can be accessed by a CPU on the local bus. Registers can be
accessed directly or indirectly through a pointer register. Accessing the registers directly provides higher
performance, while accessing the registers through the pointer register requires fewer physical address pins. The
most commonly used registers have been located at the lowest addresses, thus providing the highest performance
when using less than 5 address bits.
Each configuration register is organized as an 8-bit register, while the Endpoint Packet Buffers can be accessed
either as an 8-bit or 16-bit port, depending on the value of the Data Width bit of the LOCCTL register.
After the NET2272 is powered-up or reset, the registers are set to their default values. Writes to unused registers are
ignored, and reads from unused registers return a value of 0.
For compatibility with future revisions, reserved bits within a register should always be written with a zero.
8.2
Register Summary
Register Groups
Main Control Registers
USB Control Registers
Endpoint Registers
8.2.1 Main Control Registers
Address
Register Name
00h
01h
02h
03h
04h
1Ch
1Dh
20h
21h
22h
23h
24h
25h
REGADDRPTR
REGDATA
IRQSTAT0
IRQSTAT1
PAGESEL
DMAREQ
SCRATCH
IRQENB0
IRQENB1
LOCCTL
CHIPREV_LEGACY
LOCCTL1
CHIPREV_2272
Register Description
Register Address Pointer
Register Data
Interrupt Status Register (low byte)
Interrupt Status Register (high byte)
Endpoint Page Select Register
DMA Request Control
General Purpose Scratch-pad
Interrupt Enable Register (low byte)
Interrupt Enable Register (high byte)
Local Bus Control
Legacy Chip Silicon Revision
Local Bus Control 1
Net2272 Chip Silicon Revision
Page
56
56
56
57
57
58
58
59
59
60
60
60
61
______________________________________________________________________________ 53
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
8.2.2 USB Control Registers
Address
Register Name
18h
19h
1Ah
1Bh
30h
31h
32h
33h
34h
35h
36h
37h
40h
41h
42h
43h
44h
45h
46h
47h
USBCTL0
USBCTL1
FRAME0
FRAME1
OURADDR
USBDIAG
USBTEST
XCVRDIAG
VIRTOUT0
VIRTOUT1
VIRTIN0
VIRTIN1
SETUP0
SETUP1
SETUP2
SETUP3
SETUP4
SETUP5
SETUP6
SETUP7
Register Description
USB Control Register (low byte)
USB Control Register (high byte)
USB Frame Number (low byte)
USB Frame Number (high byte)
Our USB Address
Diagnostic register
USB 2.0 Test Control Register
USB Transceiver Diagnostic Register
Virtual OUT Interrupt 0
Virtual OUT Interrupt 1
Virtual IN Interrupt 0
Virtual IN Interrupt 1
Setup byte 0
Setup byte 1
Setup byte 2
Setup byte 3
Setup byte 4
Setup byte 5
Setup byte 6
Setup byte 7
Page
62
62
62
62
63
63
64
64
64
65
65
65
65
66
66
66
66
66
67
67
8.2.3 Endpoint Registers
Note: There is a set of endpoint registers for each endpoint. The Page Select field in the PAGESEL register selects
which set of registers is active when the following addresses are accessed.
Address
Register Name
05h
06h
07h
08h
09h
0Ah
0Bh
0Ch
0Dh
0Eh
0Fh
28h
29h
2Ah
2Bh
2Ch
EP_DATA
EP_STAT0
EP_STAT1
EP_TRANSFER0
EP_TRANSFER1
EP_TRANSFER2
EP_IRQENB
EP_AVAIL0
EP_AVAIL1
EP_RSPCLR
EP_RSPSET
EP_MAXPKT0
EP_MAXPKT1
EP_CFG
EP_HBW
EP_BUFF_STATES
Register Description
Endpoint Data Register
Endpoint Status (low byte)
Endpoint Status (high byte)
IN endpoint byte count (byte 0)
IN endpoint byte count (byte 1)
IN endpoint byte count (byte 2)
Endpoint interrupt enable
Buffer space/byte count (byte 0)
Buffer space/byte count (byte 1)
Endpoint Response Control Clear
Endpoint Response Control Set
Endpoint Maximum Packet (low byte)
Endpoint Maximum Packet (high byte)
Endpoint configuration
Endpoint high bandwidth
Endpoint buffer states
Page
68
68
69
69
69
69
70
70
70
71
72
72
72
73
73
74
______________________________________________________________________________ 54
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
8.3
NET2272 USB Peripheral Controller
Numeric Register Listing
This table shows the number of address bits required to access a register directly. If only four address bits are
supplied to the chip, then the registers that require 5 address bits must be addressed indirectly using
REGADDRPTR and REGDATA.
Addresses marked with (P) are paged registers selected by the Page Select field in the PAGESEL register.
Address
Address bits
Required
00h
01h
02h
03h
04h
05h (P)
06h (P)
07h (P)
08h (P)
09h (P)
0Ah (P)
0Bh (P)
0Ch (P)
0Dh (P)
0Eh (P)
0Fh (P)
10-17h
18h
19h
1Ah
1Bh
1Ch
1Dh
1E-1Fh
20h
21h
22h
23h
24h
25h
26-27h
28h (P)
29h (P)
2Ah (P)
2Bh (P)
2Ch (P)
2D-2Fh
30h
31h
32h
33h
34h
35h
36h
37h
38-3Fh
40h
1
1
2
2
3
3
3
3
4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
Indirect Only
Indirect Only
Indirect Only
Indirect Only
Indirect Only
Indirect Only
Indirect Only
Indirect Only
Indirect Only
Indirect Only
Indirect Only
Indirect Only
Indirect Only
Indirect Only
Indirect Only
Indirect Only
Indirect Only
Indirect Only
Indirect Only
Indirect Only
Indirect Only
Indirect Only
Indirect Only
D[15:8]
REGDATA1
EP_DATA1
D[7:0]
REGADDRPTR
REGDATA
IRQSTAT0
IRQSTAT1
PAGESEL
EP_DATA
EP_STAT0
EP_STAT1
EP_TRANSFER0
EP_TRANSFER1
EP_TRANSFER2
EP_IRQENB
EP_AVAIL0
EP_AVAIL1
EP_RSPCLR
EP_RSPSET
Reserved
USBCTL0
USBCTL1
FRAME0
FRAME1
DMAREQ
SCRATCH
Reserved
IRQENB0
IRQENB1
LOCCTL
CHIPREV_LEGACY
LOCCTL1
CHIPREV_2272
Reserved
EP_MAXPKT0
EP_MAXPKT1
EP_CFG
EP_HBW
EP_BUFF_STATES
Reserved
OURADDR
USBDIAG
USBTEST
XCVRDIAG
VIRTOUT0
VIRTOUT1
VIRTIN0
VIRTIN1
Reserved
SETUP0
Register Description
Register Address Pointer for indirect register addressing
Register Data port for indirect register addressing
Interrupt Status Register (low byte)
Interrupt Status Register (high byte)
Page Select Register. Select current Endpoint
Endpoint Data Register
Endpoint Main Status
For IN endpoint, number of bytes to transfer to host.
Endpoint Interrupt Enable
For IN endpoints, number of available spaces in buffer.
For OUT endpoints, number of bytes in buffer.
Endpoint Response Register Clear
Endpoint Response Register Set
USB Control
Frame Counter
DMA Request Control Register
General-Purpose Scratchpad register
Interrupt Enable Register
Local Bus Control Register
Legacy Chip Revision Number
Local Bus Control Register 1
Net2272 Chip Revision Number
Endpoint Max Packet Size
Endpoint Configuration
Endpoint High-Bandwidth
Endpoint Buffer States
Our USB address
Diagnostic Register
USB 2.0 Test Control Register
Transceiver Diagnostic Register
Virtual OUT Interrupt 0
Virtual OUT Interrupt 1
Virtual IN Interrupt 0
Virtual IN Interrupt 1
Setup byte 0
______________________________________________________________________________ 55
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
41h
42h
43h
44h
45h
46h
47h
NET2272 USB Peripheral Controller
Indirect Only
Indirect Only
Indirect Only
Indirect Only
Indirect Only
Indirect Only
Indirect Only
8.4
SETUP1
SETUP2
SETUP3
SETUP4
SETUP5
SETUP6
SETUP7
Setup byte 1
Setup byte 2
Setup byte 3
Setup byte 4
Setup byte 5
Setup byte 6
Setup byte 7
Main Control Registers
8.4.1 (Address 00h; REGADDRPTR) Indirect Register Address Pointer
Bits
Description
7
6:0
Reserved.
Register Address. Register Address Pointer used for indirect register addressing.
Read
Write
Default
Value
0
Yes
No
Yes
0
0
Read
Write
Default
Value
Yes
Yes
0
Read
Write
Default
Value
Yes
Yes/CLR
0
Yes
Yes/CLR
0
Yes
Yes/CLR
0
Yes
No
0
Yes
No
0
Yes
No
0
Yes
No
0
Yes
No
0
8.4.2 (Address 01h; REGDATA) Indirect Register Data
Bits
Description
15:0
Register Data. Register Data port for indirect register addressing. For 8-bit bus
widths, data is transferred on bits [7:0]. For 16-bit buffer accesses, data is transferred
on bits [15:0].
8.4.3 (Address 02h; IRQSTAT0) Interrupt Status Register (low byte)
Bits
7
6
5
4
3
2
1
0
Description
SOF Interrupt. This bit indicates when a start-of-frame packet has been received by
the NET2272. Writing a 1 clears this status bit.
DMA Done Interrupt. For IN endpoints, this bit indicates that EOT# has been
asserted, the EP_TRANSFER counter reaches zero during a DMA, or the
corresponding EP_TRANSFER counter is loaded with a 0. For OUT endpoints, this
bit indicates that EOT# has been asserted, or that a short packet has been received
and the endpoint buffers have gone empty. Writing a 1 clears this status bit. This bit
is set independently of the corresponding interrupt enable bit.
Setup Packet Interrupt. This bit is set when a setup packet has been received from
the host. Writing a 1 clears this status bit.
Virtualized Endpoint Interrupt. This bit is set when one of the Virtual Endpoint
interrupts is set.
Endpoint C Interrupt. This bit conveys the interrupt status for Endpoint C. When
set, Endpoint C’s interrupt status register should be read to determine the cause of the
interrupt. This bit is set independently of the interrupt enable bit.
Endpoint B Interrupt. This bit conveys the interrupt status for Endpoint B. When
set, Endpoint B’s interrupt status register should be read to determine the cause of the
interrupt. This bit is set independently of the interrupt enable bit.
Endpoint A Interrupt. This bit conveys the interrupt status for Endpoint A. When
set, Endpoint A’s interrupt status register should be read to determine the cause of the
interrupt. This bit is set independently of the interrupt enable bit.
Endpoint 0 Interrupt. This bit conveys the interrupt status for Endpoint 0. When
set, Endpoint 0’s interrupt status register should be read to determine the cause of the
interrupt. This bit is set independently of the interrupt enable bit.
______________________________________________________________________________ 56
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Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
8.4.4 (Address 03h; IRQSTAT1) Interrupt Status Register (high byte)
Bits
7
6
5
4
3
2
1
0
Description
Reset Status. When set, this bit indicates that either the RESET# pin is asserted, or a
USB root port reset is currently active.
Root Port Reset Interrupt. This bit indicates a change in state of the root port reset
detector. Writing a 1 clears this status bit.
Resume Interrupt. When set, this bit indicates that a device resume has occurred.
Writing a 1 clears this status bit.
Suspend Request Change Interrupt. This bit is set whenever there is a change in
the Suspend Request Interrupt state (bit 3 of this register). Writing a 1 clears this
status bit.
Suspend Request Interrupt. This bit is set when the NET2272 detects a USB
Suspend request from the host. The Suspend Request state cannot be set or cleared
by writing this bit. Instead, writing a 1 to this bit puts the NET2272 into the lowpower suspend mode (see section 7.1.1).
VBUS Interrupt. When set, this bit indicates that a change occurred on the VBUS
input pin. Read the USBCTL1 register for the current state of this pin. Writing a 1
clears this status bit.
Control Status Interrupt. This bit is set when an IN or OUT token indicating
Control Status has been received. Writing a 1 clears this status bit.
Reserved.
Read
Write
Default
Value
Yes
No
0
Yes
Yes/CLR
0
Yes
Yes/CLR
0
Yes
Yes/CLR
0
Yes
Yes/
Suspend
0
Yes
Yes/CLR
0
Yes
Yes/CLR
0
0
No
0
Read
Write
Default
Value
0
Yes
No
Yes
0
00
8.4.5 (Address 04h; PAGESEL) Endpoint Page Select Register
Bits
Description
7:2
1:0
Reserved.
Page Select. The NET2272 uses a paged architecture for accessing the registers
associated with each endpoint. This field selects which set of endpoint registers can
be accessed.
VALUE
ENDPOINT
00
01
10
11
EP 0
EP A
EP B
EP C
______________________________________________________________________________ 57
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Patent Pending
335 Pioneer Way, Mountain View, California 94041
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http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
8.4.6 (Address 1Ch; DMAREQ) DMA Request Control Register
Bits
7
6
5
4
3
2
1
0
Description
DMA Buffer Valid. When clear, the buffer will not be automatically validated at
the end of a DMA transfer. When set, the buffer is automatically validated at the end
of a DMA if EOT is asserted. This bit only applies to IN endpoints.
DMA Request. This status bit reflects the state of the DREQ output pin, and allows a
CPU on the local bus to monitor DMA transfers.
DMA Request Enable. Writing a 1 to this bit enables the NET2272 to start
requesting DMA cycles from a DMA controller on the local bus. If the EOT input is
asserted, or the EP_TRANSFER counter reaches zero, or a short OUT packet is
received and the endpoint buffer becomes empty, this bit is automatically reset. A
CPU on the local bus may also explicitly reset this bit to terminate a DMA transfer.
If the CPU writes a 0 to the EP_TRANSFER0 register of the endpoint selected by
Page Select, this bit is cleared. This bit can be read to determine whether a DMA
transfer is still in progress.
DMA Control DACK. When clear, only DACK is used to perform DMA read and
write transactions. When set, IOR# and IOW# (or DMARD# and DMAWR# for
split mode DMA) control signals are used with DACK to perform DMA read and
write transactions.
EOT Polarity. When clear, the EOT input pin is active low. When set, the EOT
input pin is active high.
DACK Polarity. When clear, the DACK input pin is active low. When set, the
DACK input pin is active high.
DREQ Polarity. When clear, the DREQ output pin is active low. When set, the
DREQ output pin is active high.
DMA Endpoint Select. This field determines which endpoint is being accessed
during a DMA channel transfer.
Value
Endpoint used during DMA
0
Endpoint A
1
Endpoint B
Read
Write
Default
Value
Yes
Yes
0
Yes
No
0
Yes
Yes
0
Yes
Yes
0
Yes
Yes
0
Yes
Yes
0
Yes
Yes
1
Yes
Yes
0
Read
Write
Default
Value
Yes
Yes
5Ah
8.4.7 (Address 1Dh; SCRATCH) Scratchpad Register
Bits
Description
7:0
SCRATCH. General-purpose scratchpad register.
______________________________________________________________________________ 58
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Patent Pending
335 Pioneer Way, Mountain View, California 94041
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http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
8.4.8 (Address 20h; IRQENB0) Interrupt Enable Register (low byte)
Bits
7
6
5
4
3
2
1
0
Description
SOF Interrupt Enable. When set, this bit enables a local interrupt to be generated
when a start-of-frame packet is received by the NET2272.
DMA Done Interrupt Enable. When set, this bit enables a local interrupt to be
generated when an EOT signal is received from the DMA controller, or when the
EP_TRANSFER counter reaches 0zero during a DMA writes to an IN endpoint.
Setup Packet Interrupt Enable. When set, this bit enables a local interrupt to be
generated when a setup packet has been received from the host.
Virtualized Endpoint Interrupt Enable. When set, this bit enables a local interrupt
to be generated when an IN or OUT token to a virtualized endpoint is detected.
Endpoint C Interrupt Enable. When set, this bit enables a local interrupt to be set
when an interrupt is active on this endpoint.
Endpoint B Interrupt Enable. When set, this bit enables a local interrupt to be set
when an interrupt is active on this endpoint.
Endpoint A Interrupt Enable. When set, this bit enables a local interrupt to be set
when an interrupt is active on this endpoint.
Endpoint 0 Interrupt Enable. When set, this bit enables a local interrupt to be set
when an interrupt is active on this endpoint.
Read
Write
Default
Value
Yes
Yes
0
Yes
Yes
0
Yes
Yes
0
Yes
Yes
0
Yes
Yes
0
Yes
Yes
0
Yes
Yes
0
Yes
Yes
0
Read
Write
Default
Value
0
Yes
No
Yes
0
0
Yes
Yes
0
Yes
Yes
0
Yes
Yes
0
Yes
Yes
0
Yes
Yes
0
0
No
0
8.4.9 (Address 21h; IRQENB1) Interrupt Enable Register (high byte)
Bits
7
6
5
4
3
2
1
0
Description
Reserved.
Root Port Reset Interrupt Enable. When set, this bit enables a local interrupt to be
generated when a root port reset is detected.
Resume Interrupt Enable. When set, this bit enables a local interrupt to be
generated when a device resume has been detected.
Suspend Request Change Interrupt Enable. When set, this bit enables a local
interrupt to be generated when a change in the Suspend Request Interrupt state is
detected.
Suspend Request Interrupt Enable. When set, this bit enables a local interrupt to
be generated when a USB Suspend Request from the host is detected.
VBUS Interrupt Enable. When set, this bit enables a local interrupt to be generated
when a change has been detected on the VBUS pin.
Control Status Interrupt Enable. When set, this bit enables a local interrupt to be
generated when an IN or OUT token indicating Control Status has been received.
Reserved.
______________________________________________________________________________ 59
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
8.4.10 (Address 22h; LOCCTL) Local Bus Control Register
Read
Write
Default
Value
Buffer Configuration. Buffer configuration for endpoints A and B. For example, if
value 01 is selected, Endpoint A will be allocated a single buffer with buffer size set
to 1024 bytes, while Endpoint B will be allocated a double buffer with each buffer
size set to 512 bytes. Actual packets sent/received can be less than or equal to the
EP_MAXPKT size for the selected endpoint. The EP_MAXPKT size must be less
than or equal to the allocated buffer size.
Value
EP_A
EP_B
00
512 db *
512 db
01
1024
512 db
10
1024
1024
11
1024 db
Disabled
* "db" means double buffered. All values shown in bytes.
Byte Swap. When clear, local data bus LD[15:0] is connected to the endpoint buffer
with no byte swapping. When set, the two bytes of a 16-bit data bus are swapped
before connecting to the endpoint buffer.
Yes
Yes
00
Yes
Yes
0
DMA Split Bus Mode. When clear, I/O and DMA accesses share the same data bus.
When set, I/O accesses to the configuration registers or buffers use LD[7:0], and
DMA accesses to the buffers use LD[15:8], thus splitting the data bus for CPU and
DMA accesses.
Local Clock Output. This field controls the frequency of the LCLKO pin.
Frequency
Value
000
0 (off)
001
3.75 MHz
010
7.5 MHz (default)
011
15 MHz
100
30 MHz
101
60 MHz
110
Reserved
111
Reserved
Data Width. This field controls the width of the local data bus for EP_DATA
accesses to endpoint buffers. Write to this register using the lower 8 bits of the data
bus to switch to 16-bit mode. This bit does not affect accesses to any other registers.
Width
Value
0
8 bits
1
16 bits
Yes
Yes
0
Yes
Yes
2
Yes
Yes
0
Bits
Description
7:6
5
4
3:1
0
8.4.11 (Address 23h; CHIPREV_LEGACY) Legacy Silicon Revision Register
Bits
Description
7:0
Legacy Chip Revision. This register returns a legacy silicon revision number for use
by Net2270 firmware.
Read
Write
Default
Value
Yes
No
‘h40
Note: The chip revision is encoded as a 2-digit BCD value. The most significant digit is the major revision number,
and the least significant digit is the minor revision number.
______________________________________________________________________________ 60
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Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
8.4.12 (Address 24h; LOCCTL1) Local Bus Control Register 1
Bits
Description
7:3
2
Reserved
DMA DACK Enable. When clear, the NET2272 does not recognize the DACK
input pin. When set, the DACK input pin is enabled. This bit is automatically set
when the DMA Request Enable bit in the DMAREQ register is set. In split DMA
mode, this bit should not be cleared if there is a possibility that DACK will be
asserted.
DMA Mode. This field determines the behavior of DREQ during DMA
transactions.
1:0
Value
00
01
10
11
Read
Write
Default
Value
Yes
Yes
No
Yes
0
0
Yes
Yes
0
Read
Write
Default
Value
Yes
No
‘h11
Description
Slow DREQ. DREQ is de-asserted several clock periods after the start of
a DMA transaction, and is re-asserted several clock periods after the end of
the DMA transactions. This mode is compatible with the Net2270.
Fast DREQ. DREQ is de-asserted at the beginning of a DMA transaction,
and is re-asserted soon after the end of the DMA transaction. This mode
provides higher DMA performance.
Burst Mode. DREQ is asserted when the DMA Request Enable bit is set
and there is space/data available in the endpoint buffer. DREQ remains
asserted until either the buffer becomes empty/full, the DMA Request
Enable bit is cleared, EOT is asserted, or EP_TRANSFER counts to 0 for
an IN endpoint.
Reserved.
8.4.13 (Address 25h; CHIPREV_2272) Net2272 Silicon Revision Register
Bits
Description
7:0
Chip Revision. This register returns the Net2272 silicon revision number.
Note: The chip revision is encoded as a 2-digit BCD value. The most significant digit is the major revision number,
and the least significant digit is the minor revision number.
______________________________________________________________________________ 61
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Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
8.5
NET2272 USB Peripheral Controller
USB Control Registers
8.5.1 (Address 18h; USBCTL0) USB Control Register (low byte)
Bits
Description
7:6
5
Reserved
USB Root Port Wakeup Enable. When clear, the wake-up condition is not
detected. When set, the root port wake-up condition is detected when activity is
detected on the USB.
Reserved.
USB Detect Enable. When clear, the NET2272 does not appear to be connected to
the USB host. When set, the NET2272 appears to be connected to the USB host.
This bit should not be set until the configuration registers have been programmed.
When operating as a bus-powered device, the registers should be programmed and
this bit should be set promptly after VBUS has been detected.
Reserved.
I/O Wakeup Enable. When clear, asserting CS# will not cause a device remote
wakeup. When set, this bit enables the assertion of CS# to initiate a device remote
wakeup.
Reserved.
4
3
2
1
0
8.5.2
Description
7:5
4
Reserved.
Virtual Endpoint Enable. When set, this bit enables the virtual endpoint feature of
the Net2272. A NAK is returned to the USB host if an IN or TOKEN is received for
an endpoint that is virtualized.
Generate Resume. Writing a 1 to this bit causes a Resume sequence to be initiated
to the host if device remote wakeup is enabled. This bit should be written after a
device remote wakeup has been generated (CS# pin asserted). This bit is selfclearing, and reading always returns a 0.
USB High Speed. When set, this bit indicates that the transceiver is operating in
high speed (480 Mbits/sec) mode.
USB Full Speed. When set, this bit indicates that the transceiver is operating in full
speed (12 Mbits/sec) mode.
VBUS pin. This bit indicates the state of the VBUS pin. When set, this bit indicates
that the NET2272 is connected to the USB.
2
1
0
Write
Default
Value
Yes
Yes
No
Yes
11
1
Yes
Yes
Yes
Yes
0
0
Yes
Yes
No
Yes
0
0
Yes
No
0
Read
Write
Default
Value
0
Yes
No
Yes
0
0
No
Yes/
Resume
0
Yes
No
0
Yes
No
0
Yes
No
0
Read
Write
Default
Value
Yes
No
0
Read
Write
Default
Value
0
Yes
No
No
0
0
(Address 19h; USBCTL1) USB Control Register (high byte)
Bits
3
Read
8.5.3 (Address 1Ah; FRAME0) Frame Counter (low byte)
Bits
Description
7:0
FRAME[7:0]. This field contains the frame counter from the most recent start-offrame packet.
8.5.4 (Address 1Bh; FRAME1) Frame Counter (high byte)
Bits
Description
7:3
2:0
Reserved.
FRAME[10:8]. This field contains the frame counter from the most recent start-offrame packet.
______________________________________________________________________________ 62
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Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
8.5.5 (Address 30h; OURADDR) Our Current USB Address
Bits
7
6:0
Description
Force Immediate. If this bit is set when this register is being written, the NET2272
USB address is updated immediately, without waiting for a valid status phase from
the USB host.
Our Address. This field contains the current USB address of the device. This field
is cleared when a root port reset is detected. After this field is written, the register
isn’t actually updated until the corresponding status phase of the control write
transfer completes successfully. This feature allows the firmware to write this field
as soon as the Setup packet is received, rather than waiting for a successful status
phase. Refer to sections 9.2.6.3 and 9.4.6 of the USB 2.0 specification.
Read
Write
Default
Value
0
Yes/Force
0
Yes
Yes
0
Read
Write
Default
Value
Yes
Yes
No
Yes
0
0
Yes
Yes
No
Yes/Set
0
0
Yes
Yes/Set
0
Yes
Yes/Set
0
8.5.6 (Address 31h; USBDIAG) USB Diagnostic Register
Bits
Description
7:5
4
Reserved
Fast Times. When this bit is set, the frame counter operates at a fast speed for
factory chip testing purposes only.
Reserved.
Force Receive Error. When this bit is set, an error is forced on the next received
data packet. As a result, the packet will not be acknowledged. This bit is
automatically cleared at the end of the next packet.
Prevent Transmit Bit-Stuff. When this bit is set, normal bit-stuffing is suppressed
during the next transmitted data packet. This will cause a bit-stuffing error when six
or more consecutive bits of ‘1’ are in the data stream. This bit is automatically
cleared at the end of the next packet.
Force Transmit CRC Error. When this bit is set, a CRC error is forced on the next
transmitted data packet. Inverting the most significant bit of the calculated CRC
generates the CRC error. This bit is automatically cleared at the end of the next
packet.
3
2
1
0
______________________________________________________________________________ 63
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Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
8.5.7 (Address 32h; USBTEST) USB Test Modes
Bits
Description
7:3
2:0
Reserved.
Test Mode Select.
Value
000
001
010
011
100
101
110
111
Read
Write
Default
Value
Yes
Yes
No
Yes
0
0
Read
Write
Default
Value
Yes
No
-
Yes
No
--
Yes
Yes
0
Yes
Yes
0
Yes
No
-
Read
Write
Default
Value
Yes
Yes/Clr
0
Yes
No
0
See sections 7.1.20 and 9.4.9 of the USB 2.0 specification.
Test
Normal Operation
Test_J
Test_K
Test_SE0_NAK
Test_Packet
Test_Force_Enable
Reserved
Reserved
8.5.8 (Address 33h; XCVRDIAG) Transceiver Diagnostic Register
Bits
Description
7:6
Linestate. This field indicates the state of the DM (Linestate[1]) and DP
(Linestate[0]) USB data signals.
[DM,DP]
Description
00
SE0 (Single-ended zero)
01
“J” state (idle)
10
“K” state (resume)
11
SE1 (Single-ended one)
Opmode. This field indicates the operational state of the transceiver.
Value
Description
00
normal operation
01
non-driving
10
disable bit stuffing and NRZI endcoding
11
reserved
Force High Speed. When this bit is high, the transceiver is forced into high-speed
mode (480 Mbps).
Force Full Speed. When this bit is high, the transceiver is forced into full-speed
mode (12 Mbps).
Reserved.
5:4
3
2
1:0
8.5.9 (Address 34h; VIRTOUT0) Virtual OUT 0
Bits
Description
7:1
Virtual OUT Interrupts. These bits are set when the Virtual Endpoint Enable bit is
set, and an OUT token is received by a virtual endpoint that is not mapped to a
physical endpoint. Bit 1 corresponds to OUT Endpoint Number 1, and bit 7
corresponds to OUT Endpoint Number 7. Writing a 1 to a bit clears that bit.
Reserved.
0
______________________________________________________________________________ 64
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Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
8.5.10 (Address 35h; VIRTOUT1) Virtual OUT 1
Bits
Description
7:0
Virtual OUT Interrupts. These bits are set when the Virtual Endpoint Enable bit is
set, and an OUT token is received by a virtual endpoint that is not mapped to a
physical endpoint. Bit 0 corresponds to OUT Endpoint Number 8, and bit 7
corresponds to OUT Endpoint Number 15. Writing a 1 to a bit clears that bit.
Read
Write
Default
Value
Yes
Yes/Clr
0
Read
Write
Default
Value
Yes
Yes/Clr
0
Yes
No
0
Read
Write
Default
Value
Yes
Yes/Clr
0
Read
Write
Default
Value
Yes
No
0
8.5.11 (Address 36h; VIRTIN0) Virtual IN 0
Bits
Description
7:1
Virtual IN Interrupts. These bits are set when the Virtual Endpoint Enable bit is
set, and an IN token is received by a virtual endpoint that is not mapped to a physical
endpoint. Bit 1 corresponds to IN Endpoint Number 1, and bit 7 corresponds to IN
Endpoint Number 7. Writing a 1 to a bit clears that bit.
Reserved.
0
8.5.12 (Address 37h; VIRTIN1) Virtual IN 1
Bits
Description
7:0
Virtual IN Interrupts. These bits are set when the Virtual Endpoint Enable bit is
set, and an IN token is received by a virtual endpoint that is not mapped to a physical
endpoint. Bit 0 corresponds to IN Endpoint Number 8, and bit 7 corresponds to IN
Endpoint Number 15. Writing a 1 to a bit clears that bit.
8.5.13 (Address 40h; SETUP0) Setup Byte 0
Bits
Description
7:0
Setup Byte 0. This register provides byte 0 of the last setup packet received. For a
Standard Device Request, the following bmRequestType information is returned.
Refer to section 9.3 of the USB 2.0 specification.
Bit
Description
7
Direction: 0 = host to device; 1 = device to host
6:5
Type: 0 = Standard, 1 = Class, 2 = Vendor, 3 = Reserved
4:0
Recipient: 0 = Device, 1 = Interface, 2 = Endpoint, 3 = Other,
4-31 = Reserved
______________________________________________________________________________ 65
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335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
8.5.14 (Address 41h; SETUP1) Setup Byte 1
Bits
Description
7:0
Setup Byte 1. This register provides byte 1 of the last setup packet received. For a
Standard Device Request, the following bRequest Code information is returned.
Refer to section 9.4 of the USB 2.0 specification.
Description
Code
00h
Get Status
01h
Clear Feature
02h
Reserved
03h
Set Feature
04h
Reserved
05h
Set Address
06h
Get Descriptor
07h
Set Descriptor
08h
Get Configuration
09h
Set Configuration
0Ah
Get Interface
0Bh
Set Interface
0Ch
Synch Frame
Read
Write
Default
Value
Yes
No
0
Read
Write
Default
Value
Yes
No
0
Read
Write
Default
Value
Yes
No
0
Read
Write
Default
Value
Yes
No
0
Read
Write
Default
Value
Yes
No
0
8.5.15 (Address 42h; SETUP2) Setup Byte 2
Bits
Description
7:0
Setup Byte 2. This register provides byte 2 of the last setup packet received. For a
Standard Device Request, the least significant byte of the wValue field is returned.
Refer to section 9.3.3 of the USB 2.0 specification.
8.5.16 (Address 43h; SETUP3) Setup Byte 3
Bits
Description
7:0
Setup Byte 3. This register provides byte 3 of the last setup packet received. For a
Standard Device Request, the most significant byte of the wValue field is returned.
Refer to section 9.3.3 of the USB 2.0 specification.
8.5.17 (Address 44h; SETUP4) Setup Byte 4
Bits
Description
7:0
Setup Byte 4. This register provides byte 4 of the last setup packet received. For a
Standard Device Request, the least significant byte of the wIndex field is returned.
Refer to section 9.3.4 of the USB 2.0 specification.
8.5.18 (Address 45h; SETUP5) Setup Byte 5
Bits
Description
7:0
Setup Byte 5. This register provides byte 5 of the last setup packet received. For a
Standard Device Request, the most significant byte of the wIndex field is returned.
Refer to section 9.3.4 of the USB 2.0 specification.
______________________________________________________________________________ 66
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335 Pioneer Way, Mountain View, California 94041
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Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
8.5.19 (Address 46h; SETUP6) Setup Byte 6
Bits
Description
7:0
Setup Byte 6. This register provides byte 6 of the last setup packet received. For a
Standard Device Request, the least significant byte of the wLength field is returned.
Refer to section 9.3.3 of the USB 2.0 specification.
Read
Write
Default
Value
Yes
No
0
Read
Write
Default
Value
Yes
No
0
8.5.20 (Address 47h; SETUP7) Setup Byte 7
Bits
Description
7:0
Setup Byte 7. This register provides byte 7 of the last setup packet received. For a
Standard Device Request, the most significant byte of the wLength field is returned.
Refer to section 9.3.3 of the USB 2.0 specification.
______________________________________________________________________________ 67
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335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
8.6
NET2272 USB Peripheral Controller
Endpoint Registers
There are 4 sets of endpoint registers, one for each endpoint. To access an endpoint, set the Page Select field of the
PAGESEL register to the desired endpoint, then read or write to an endpoint register as defined below. Status bits
associated with an endpoint packet buffer (Buffer Full, Buffer Empty, etc), are only valid for the currently visible
buffer. The currently visible buffer is the one that is currently being written to or read from by the local bus.
8.6.1 (Address 05h; EP_DATA) Endpoint Data
Note: If DMA Request is enabled, then this register accesses the endpoint buffer selected by DMA Endpoint Select,
rather than Page Select.
Bits
Description
15:8
Endpoint Data (High Order byte). When operating with a bus width of 16 bits,
bits [15:8] of this register provide the high order byte.
Endpoint Data (Low Order byte). When operating with a bus width of 8 bits, bits
[7:0] of this register provide the data for the buffer transaction (read or write). When
operating with a bus width of 16 bits, bits [7:0] of this register provide the low order
byte.
7:0
Read
Write
Default
Value
Yes
Yes
0
Yes
Yes
0
8.6.2 (Address 06h; EP_STAT0) Endpoint Status Register (low byte)
Note 1: If DMA Request is enabled, then the Buffer Full and Buffer Empty bits correspond to the endpoint buffer
selected by DMA Endpoint Select, rather than Page Select.
Note 2: The Buffer Full and Buffer Empty bits take up to 100 nsec to become valid after an endpoint buffer is written
or read.
Bits
7
6
5
4
3
2
1
0
Description
Buffer Full. This bit is set when the endpoint packet buffer is full. For an IN
endpoint, the currently selected buffer has a count of MaxPkt bytes, or no buffer is
available to the local side for writing (no space to write). For an OUT endpoint,
there is a buffer available on the local side, and there are MaxPkt bytes available to
read (entire packet is available for reading).
Buffer Empty. For an IN endpoint, a buffer is available to the local side for writing
up to MaxPkt bytes. This bit is set when the endpoint buffer is empty. For an OUT
endpoint, the currently selected buffer has a count of 0, or no buffer is available on
the local side (nothing to read).
NAK OUT Packets. This bit is set when a short data packet is received from the host
by this endpoint, and the NAK OUT Packets Mode bit of the EP_RSPSET register is
set. Writing a 1 clears this status bit. If this bit is set and another OUT token is
received, a NAK is returned to the host if another OUT packet is sent to this
endpoint. This bit can also be controlled by the EP_RSPCLR and EP_RSPSET
registers.
Short Packet Transferred Interrupt. This bit is set when the length of the last
packet was less than the Maximum Packet Size (EP_MAXPKT). Writing a 1 clears
this bit.
Data Packet Received Interrupt. This bit is set when a data packet is received from
the host by this endpoint. Writing a 1 clears this bit.
Data Packet Transmitted Interrupt. This bit is set when a data packet is
transmitted from the endpoint to the host. Writing a 1 clears this bit.
Data OUT Token Interrupt. This bit is set when a Data OUT token has been
received from the host. This bit is also set by PING tokens (in high-speed
only). Writing a 1 clears this bit.
Data IN Token Interrupt. This bit is set when a Data IN token has been received
from the host. Writing a 1 clears this bit.
Read
Write
Default
Value
Yes
No
0
Yes
No
1
Yes
Yes/CLR
0
Yes
Yes/CLR
0
Yes
Yes/CLR
0
Yes
Yes/CLR
0
Yes
Yes/CLR
0
Yes
Yes/CLR
0
______________________________________________________________________________ 68
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Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
8.6.3 (Address 07h; EP_STAT1) -- Endpoint Status Register (high byte)
Bits
7
6
5
4
3
2
1
0
Description
Buffer Flush. Writing a 1 to this bit causes the packet buffer to be flushed and the
corresponding EP_AVAIL register to be cleared. This bit is self-clearing. This bit
should always be written after an endpoint configuration (direction, address, etc.) has
been changed. This bit should not be asserted during a split-mode DMA if Page
Select is selecting another endpoint.
Local OUT ZLP. When set, this bit indicates that the current local buffer contains a
zero length packet.
USB STALL Sent. The last USB packet could not be accepted or provided because
the endpoint was stalled, and was acknowledged with a STALL. Writing a 1 clears
this bit.
USB IN NAK Sent. The last USB IN packet could not be provided, and was
acknowledged with a NAK. Writing a 1 clears this bit.
USB IN ACK Rcvd. The last USB IN data packet transferred was successfully
acknowledged with an ACK from the host. Writing a 1 clears this bit.
USB OUT NAK Sent. The last USB OUT data packet could not be accepted, and
was acknowledged with a NAK to the host. Writing a 1 clears this bit.
USB OUT ACK Sent. The last USB OUT data packet transferred was successfully
acknowledged with an ACK to the host. Writing a 1 clears this bit.
Timeout. For an IN endpoint, the last USB packet transmitted was not acknowledged
by the Host PC, indicating a bus error. The Host PC will expect the same packet to be
retransmitted in response to the next IN token. For an OUT endpoint, the last USB
packet received had a CRC or bit-stuffing error, and was not acknowledged by the
NET2272. The Host PC will retransmit the packet. Writing a 1 clears this bit.
Read
Write
Default
Value
0
Yes/Flush
0
Yes
No
0
Yes
Yes/CLR
0
Yes
Yes/CLR
0
Yes
Yes/CLR
0
Yes
Yes/CLR
0
Yes
Yes/CLR
0
Yes
Yes/CLR
0
8.6.4 (Address 08h; EP_TRANSFER0) Transfer Count Register (Byte 0)
Bits
Description
7:0
EP_TRANSFER[7:0]. For IN endpoints, this field determines the total number of
bytes to be sent to the host. This field should be written before any packet data is
written to the buffer. When the count reaches zero, any remaining data in the buffer
is validated. Note that validation takes about 100 nsec. Writing zero to
EP_TRANSFER0 when EP_TRANSFER1 and EP_TRANSFER2 have a value of
0 validates the contents of this IN endpoint buffer regardless of the state of the Auto
Validate bit; if the buffer is empty, writing zero to EP_TRANSFER0 validates a
Zero Length Packet.
Read
Write
Default
Value
Yes
Yes
0
Read
Write
Default
Value
Yes
Yes
0
Read
Write
Default
Value
Yes
Yes
0
For OUT endpoints, this counter is cleared when the NAK OUT packets bit is cleared
(EP_RSPCLR bit 7). This counter is incremented for every byte read from the
packet buffer. If 16-bit mode is selected and only one of the two bytes is valid, the
counter will only increment by 1.
8.6.5 (Address 09h; EP_TRANSFER1) Transfer Count Register (Byte 1)
Bits
Description
7:0
EP_TRANSFER[15:8].
8.6.6 (Address 0Ah; EP_TRANSFER2) Transfer Count Register (Byte 2)
Bits
Description
7:0
EP_TRANSFER[23:16].
______________________________________________________________________________ 69
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Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
8.6.7 (Address 0Bh; EP_IRQENB) Endpoint Interrupt Enable Register
Bits
Description
7:5
4
Reserved.
Short Packet Transferred Interrupt Enable. When set, this bit enables a local
interrupt to be set when a short data packet has been transferred to/from the host.
Data Packet Received Interrupt Enable. When set, this bit enables a local interrupt
to be set when a data packet has been received from the host.
Data Packet Transmitted Interrupt Enable. When set, this bit enables a local
interrupt to be set when a data packet has been transmitted to the host.
Data OUT Token Interrupt Enable. When set, this bit enables a local interrupt to
be set when a Data OUT token has been received from the host.
Data IN Token Interrupt Enable. When set, this bit enables a local interrupt to be
set when a Data IN token has been received from the host.
3
2
1
0
Read
Write
Default
Value
0
Yes
No
Yes
0
0
Yes
Yes
0
Yes
Yes
0
Yes
Yes
0
Yes
Yes
0
8.6.8 (Address 0Ch: EP_AVAIL0) Endpoint Available Count (low byte)
Note: If DMA Request is enabled, then the value in this register corresponds to the endpoint buffer selected by DMA
Endpoint Select, rather than Page Select.
Bits
Description
7:0
EP_AVAIL[7:0]. For an OUT endpoint, this register returns the number of valid
bytes in the endpoint packet buffer. Values range from 0 (empty) to 1024 (full).
Read
Write
Default
Value
Yes
No
0
Read
Write
Default
Value
Yes
Yes
No
No
0
0
For an IN endpoint, this register returns the number of empty bytes in the packet
buffer. Values range from 0 (full) to 1024 (empty). This field is updated either after
2 bytes have been written to the buffer, or when the buffer has been validated.
If only the low byte of this field is read, the entire 11-bit field is frozen until the
upper byte is read.
8.6.9 (Address 0Dh: EP_AVAIL1) Endpoint Available Count (high byte)
Bits
Description
7:3
2:0
Reserved.
EP_AVAIL[10:8].
______________________________________________________________________________ 70
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335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
8.6.10 (Address 0Eh; EP_RSPCLR) Endpoint Response Register Clear
Note: Writing a 1 to bits 7:0 clears the corresponding register bits.
Bits
7
6
5
4
3
2
1
0
Description
Alt NAK OUT Packets. This bit is set when a short data packet is received from the
host by this endpoint, and the NAK OUT Packets Mode bit is set. If this bit is set and
another OUT token is received, a NAK is returned to the host if another OUT packet
is sent to this endpoint. This bit can also be cleared by a bit in the EP_STAT0
register.
Hide Status Phase. When set, the DATA Packet Received and Data Packet
Transmitted interrupts for status phase packets are not set.
Auto Validate. When set, this bit allows automatic validation of maximum length
packets. Automatic validation means that if there are EP_MAXPKT bytes in the
endpoint buffer, the data is returned to the USB host in response to the next IN token
without being manually validated by the local CPU. This is the normal mode of
operation for endpoint transactions and is the default state for this bit. When this bit
is clear, packets must be manually validated. Writing zero to EP_TRANSFER0
when EP_TRANSFER1 and EP_TRANSFER2 have a value of 0 validates the
contents of this IN endpoint buffer regardless of the state of the Auto Validate bit; if
the buffer is empty, writing zero to EP_TRANSFER0 validates a Zero Length
Packet.
Interrupt Mode. This bit is only used for INTERRUPT endpoints. For normal
interrupt data, this bit should be set to zero and standard data toggle protocol is
followed. When this interrupt endpoint is used for isochronous rate feedback
information, this bit should be set high. In this mode the data toggle bit is changed
after each packet is sent to the host without regard to handshaking. No packet retries
are performed in the rate feedback mode.
Control Status Phase Handshake. This bit is only used for endpoint 0. This bit is
automatically set when a setup packet is detected. While the bit is set, a control status
phase will be acknowledged with a NAK. Once cleared, the proper response will be
returned to the host (ACK for Control Reads and zero-length packets for Control
Writes).
NAK OUT Packets Mode. This bit is only used for OUT endpoints. When NAK
OUT Packets Mode is true, the NAK OUT Packets bit is set whenever a short packet
is received by this endpoint.
Endpoint Toggle. This bit is used to clear the endpoint data toggle bit. Reading this
bit returns the current state of the endpoint data toggle bit. Under normal operation,
the toggle bit is controlled automatically, so the local CPU does not need to use this
bit.
Endpoint Halt. This bit is used to clear the endpoint stall bit. When an Endpoint Set
Feature Standard Request to the halt bit is detected by the local CPU, it must write a
1 to this bit. Reading this bit returns the current state of the endpoint halt bit. For
Endpoint 0, the halt bit is automatically cleared when another Setup packet is
received.
Read
Write
Default
Value
Yes
Yes/Clr
0
Yes
Yes/Clr
0
Yes
Yes/Clr
1
Yes
Yes/Clr
0
Yes
Yes/Clr
0
Yes
Yes/Clr
1
Yes
Yes/Clr
0
Yes
Yes/Clr
0
______________________________________________________________________________ 71
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Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
8.6.11 (Address 0Fh; EP_RSPSET) Endpoint Response Register Set
Note: Writing a 1 to bits 7:0 sets the corresponding register bits.
Bits
7
6
5
4
3
2
1
0
Description
Alt NAK OUT Packets.
Hide Status Phase.
Auto Validate.
Interrupt Mode.
Control Status Phase Handshake.
NAK OUT Packets Mode.
Endpoint Toggle.
Endpoint Halt.
Read
Write
Default
Value
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes/Set
Yes/Set
Yes/Set
Yes/Set
Yes/Set
Yes/Set
Yes/Set
Yes/Set
0
0
1
0
0
1
0
0
Read
Write
Yes
Yes
Read
Write
Default
Value
Yes
Yes
No
Yes
0
0
Yes
Yes
EP0 = 64
EPA = 512
EPB = 512
EPC = 512
8.6.12 (Address 28h; EP_MAXPKT0) Max Packet Size (low byte)
Bits
Description
7:0
EP_MAXPKT[7:0]. This field determines the Endpoint Maximum Packet Size.
Default
Value
EP0 = 64
EPA = 512
EPB = 512
EPC = 512
8.6.13 (Address 29h; EP_MAXPKT1) Max Packet Size (high byte)
Bits
Description
7:5
4:3
Reserved.
Additional Transaction Opportunities. This field determines the number of
additional transaction opportunities per microframe for high-speed isochronous and
interrupt endpoints.
00 = None (1 transaction per microframe)
01 = 1 additional (2 per microframe)
10 = 2 additional (3 per microframe)
11 = Reserved
EP_MAXPKT[10:8]. This field determines the Endpoint Maximum Packet Size.
2:0
______________________________________________________________________________ 72
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335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
8.6.14 (Address 2Ah; EP_CFG) Endpoint Configuration Register
NOTE: For Endpoint 0, all fields in this register, except Endpoint Direction, are assigned to fixed values, and are
RESERVED.
Bits
7
6:5
4
3:0
Description
Endpoint Enable. When set, this bit enables this endpoint. This bit has no effect on
Endpoint 0, which is always enabled. When this bit is cleared, it will not read back
as a zero until all pending USB transactions on the endpoint have completed.
Endpoint Type. This field selects the type of this endpoint. Endpoint 0 is forced to a
Control type.
Description
Value
0
Reserved
1
Isochronous
2
Bulk
3
Interrupt
Endpoint Direction. This bit selects the direction of the endpoint selected by Page
Select. EP_DIR = 0 means Host OUT to Device, while EP_DIR = 1 means Host IN
from Device. Endpoint 0 is bi-directional, and uses this bit for a test mode. When
set, endpoint packet buffers can be read back for diagnostics. Note that a maximum
of one OUT and IN endpoint is allowed for each endpoint number.
For endpoint 0, this bit is dynamic, and depends on the direction bit in the last Setup
packet.
Endpoint Number. This field selects the number of the endpoint. Valid numbers are
0 to 15. This field has no effect on Endpoint 0, which always has an endpoint number
of 0.
Read
Write
Default
Value
Yes
Yes
0
Yes
Yes
0
Yes
Yes
0
Yes
Yes
0
Read
Write
Default
Value
Yes
Yes
No
No
0
0
8.6.15 (Address 2Bh: EP_HBW) Endpoint High Bandwidth
Bits
Description
7:2
1:0
Reserved.
High-Bandwidth OUT Transaction PID. This field provides the PID of the last
high bandwidth OUT packet received. It is stable when the Data Packet Received
Interrupt bit is set, and remains stable until another OUT packet is received. It is
based on the currently active buffer.
PID
Value
00
DATA0
01
DATA1
10
DATA2
11
MDATA
______________________________________________________________________________ 73
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Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
8.6.16 (Address 2Ch: EP_BUFF_STATES) Endpoint Buffer States
Bits
Description
7:4
3:2
Reserved.
Buffer B State. This field provides the current state of the endpoint buffer B.
Value
State
00
Buff_Free; buffer is empty, free to assign
01
Buff_Valid; buffer has valid packet, waiting to move to local or USB side
10
Buff_Lcl; buffer is assigned to the local side
11
Buff_Usb; buffer is assigned to the USB side
Buffer A State. This field provides the current state of the endpoint buffer A.
State
Value
00
Buff_Free; buffer is empty, free to assign
01
Buff_Valid; buffer has valid packet, waiting to move to local or USB side
10
Buff_Lcl; buffer is assigned to the local side
11
Buff_Usb; buffer is assigned to the USB side
1:0
Read
Write
Default
Value
Yes
Yes
No
No
0
--
Yes
No
--
IN packets move: Lcl -> Valid -> Usb -> Free
OUT packets move: Usb -> Valid -> Lcl -> Free
If an endpoint is double-buffered, the buffers are never in the same state. If an endpoint is single-buffered, the
unused (B) buffer is locked to the Buff_Free state.
8.7
Register Changes from Net2270
•
•
•
•
•
•
•
•
•
•
•
•
Add Virtualized Endpoint Interrupt Enable to IRQENB0[4].
Add Virtualized Endpoint Interrupt Status to IRQSTAT0[4].
Add new LOCCTL1 register. Add DMA Mode bit to LOCCTL1[1:0].
Add Virtual Endpoint Enable bit to USBCTL[4].
Add Virtual OUT Interrupt 0 register (VIRTOUT0).
Add Virtual OUT Interrupt 1 register (VIRTOUT1).
Add Virtual IN Interrupt 0 register (VIRTIN0).
Add Virtual IN Interrupt 1 register (VIRTIN1).
Add Local OUT ZLP status bit to EP_STAT1[6].
Add new EP_HBW register.
Add new EP_BUFF_STATES register.
Remove Force Bi-directional to Inputs bit from USBDIAG register.
______________________________________________________________________________ 74
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335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
9 USB Standard Device Requests
Standard device requests must be supported by Endpoint 0. See also chapter 9, USB specification. The local bus
CPU decodes the setup packets for Endpoint 0 and generates a response based on the following tables
Table 9-1: Standard Request Codes
bRequest
Get_Status
Clear_Feature
Reserved
Set_Feature
Reserved
Set_Address
Get_Descriptor
Set_Descriptor
Get_Configuration
Set_Configuration
Get_Interface
Set_Interface
Synch_Frame
Value
0
1
2
3
4
5
6
7
8
9
Ah
Bh
Ch
Table 9-2. Descriptor Types
Descriptor Types
Device
Configuration
String
Interface
Endpoint
Device Qualifier
Other_Speed_Configuration
Interface Power
Value
1
2
3
4
5
6
7
8
______________________________________________________________________________ 75
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Rev 1.2, October 15, 2003
Specification
9.1
NET2272 USB Peripheral Controller
Control ‘Read’ Transfers
9.1.1 Get Device Status
Offset
Number of
Bytes
0
2
Description
bits 15:2 = Reserved
bit 1 = Device Remote Wakeup enabled
bit 0 = Power supply is good in Self-Powered mode.
Suggested Value
Determined by local CPU
9.1.2 Get Interface Status
Offset
Number of
Bytes
0
2
Description
bits 15:0 = Reserved
Suggested Value
0000h
9.1.3 Get Endpoint Status
Offset
Number of
Bytes
0
2
Description
bits 15:1 = Reserved
bit 0 = Endpoint is halted
Suggested Value
Determined by local CPU
9.1.4 Get Device Descriptor (18 Bytes)
Offset
Number of
Bytes
0
1
2
4
5
6
7
8
10
12
14
15
16
17
1
1
2
1
1
1
1
2
2
2
1
1
1
1
Description
Length
Type (device)
USB Specification Release Number
Class Code
Sub Class Code
Protocol
Maximum Endpoint 0 Packet Size
Vendor ID
Product ID
Device Release Number
Index of string descriptor describing manufacturer
Index of string descriptor describing product
Index of string descriptor describing serial number
Number of configurations
Suggested Value
12h
01h
0200h
FFh
00h
00h
40h
0525h
2272h
0110h
01h
02h
00h (not enabled)
Determined by local CPU
______________________________________________________________________________ 76
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Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
9.1.5 Get Device Qualifier (10 Bytes)
Offset
Number of
Bytes
0
1
2
4
5
6
7
8
9
1
1
2
1
1
1
1
1
1
Description
Length
Type (device qualifier)
USB Specification Release Number
Class Code
Sub Class Code
Protocol
Maximum Endpoint 0 Packet Size for other speed
Number of other-speed configurations
Reserved
Suggested Value
0Ah
06h
0200h
FFh
00h
00h
40h
Determined by local CPU
00h
9.1.6 Get Other_Speed_Configuration Descriptor
The structure of the other_speed_cofiguration is identical to a configuration descriptor, except that the
bDescriptorType is 7 instead of 2.
______________________________________________________________________________ 77
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335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
9.1.7 Get Configuration Descriptor
The NET2272 can support a variety of configurations, interfaces, and endpoints, each of which is defined by the
descriptor data returned to the host. The local CPU has the responsibility of providing this data to the NET2272
when the host requests it.
This example has one configuration, and two interfaces. The first interface defines one Bulk OUT endpoint at
address 1 with maximum packet size of 512 and one Interrupt IN endpoint at address 82h (endpoint number = 2)
with a maximum packet size of 8. The second interface defines one Bulk OUT endpoint at address 3 with maximum
packet size of 512.
Note that all interface and endpoint descriptors are returned in response to a Get Configuration Descriptor request,
and for this example, 48 bytes are returned.
Offset
Number of
Bytes
Configuration Descriptor
0
1
2
4
5
6
7
1
1
2
1
1
1
1
8
1
Description
Suggested Value
Length
Type (configuration)
Total length returned for this configuration
Number of Interfaces
Number of this configuration
Index of string descriptor describing this configuration
Attributes
bit 7 = 1
bit 6 = Self-Powered
bit 5 = Remote-Wakeup
bits 4:0 = Reserved
Maximum USB power required (in 2 mA units)
09h
02h
0030h
02h
01h
00h
Determined by Local CPU
Determined by Local CPU
Interface 0 Descriptor
0
1
2
3
4
1
1
1
1
1
5
6
7
8
1
1
1
1
Size of this descriptor in bytes
Type (interface)
Number of this interface
Alternate Interface
Number of endpoints used by this interface
(excluding Endpoint 0)
Class Code
Sub Class Code
Device Protocol
Index of string descriptor describing this interface
09h
04h
00h
00h
02h
FFh
00h
00h
00h
______________________________________________________________________________ 78
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Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
Get Configuration Descriptor (continued)
Offset
Number of
Description
Bytes
Bulk OUT Endpoint 1 Descriptor
Suggested Value
0
1
2
1
1
1
07h
05h
01h
3
1
4
6
2
1
Size of this descriptor
Descriptor Type (endpoint)
Endpoint Address
bit 7 = direction (1 = IN, 0 = OUT)
bits 6:4 = reserved
bits 3:0 = endpoint number
Endpoint Attributes
bits 7:2 = reserved
bits 1:0
00 = Control
01 = Isochronous
10 = Bulk
11 = Interrupt
Maximum packet size of this endpoint
Maximum NAK rate of the endpoint.
02h
0200h
Determined by Local CPU
Interrupt IN Endpoint 2 Descriptor
0
1
2
1
1
1
3
1
4
2
6
1
Size of this descriptor
Descriptor Type (endpoint)
Endpoint Address
bit 7 = direction (1 = IN, 0 = OUT)
bits 6:4 = reserved
bits 3:0 = endpoint number
Endpoint Attributes
bits 7:2 = reserved
bits 1:0
00 = Control
01 = Isochronous
10 = Bulk
11 = Interrupt
bits 10:0 = Maximum packet size of this endpoint.
(Determined by the EP_MAXPKT registers).
bits 12:11 = Number of additional transaction
opportunities per microframe:
00 = None (1 transaction per microframe)
01 = 1 additional (2 per microframe)
10 = 2 additional (3 per microframe)
11 = Reserved
Bits 15:13 = reserved
Interval for polling endpoint
07h
05h
82h
03h
0008h
Determined by Local CPU
______________________________________________________________________________ 79
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335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
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Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
Get Configuration Descriptor (continued)
Offset
Number of
Description
Bytes
Interface 1 Descriptor
Suggested Value
0
1
2
3
4
1
1
1
1
1
09h
04h
01h
00h
01h
5
6
7
8
1
1
1
1
Size of this descriptor in bytes
Type (interface)
Number of this interface
Alternate Interface
Number of endpoints used by this interface
(excluding Endpoint 0)
Class Code
Sub Class Code
Device Protocol
Index of string descriptor describing this interface
FFh
00h
00h
00h
Bulk OUT Endpoint 3 Descriptor
0
1
2
1
1
1
3
1
4
6
2
1
Size of this descriptor
Descriptor Type (endpoint)
Endpoint Address
bit 7 = direction (1 = IN, 0 = OUT)
bits 6:4 = reserved
bits 3:0 = endpoint number
Endpoint Attributes
bits 7:2 = reserved
bits 1:0
00 = Control
01 = Isochronous
10 = Bulk
11 = Interrupt
Maximum packet size of this endpoint for bulk mode
Maximum NAK rate of the endpoint.
07h
05h
03h
02h
0200h
Determined by Local CPU
______________________________________________________________________________ 80
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
9.1.8 Get String Descriptor 0
Offset
Number of
Bytes
Description
Suggested Value
0
1
2
1
1
2
Size of this descriptor in bytes
Descriptor type (string)
Language ID (English = 09, U.S. = 04)
04h
03h
0409h
9.1.9 Get String Descriptor 1
Offset
Number of
Bytes
Description
Suggested Value
0
1
2
1
1
36
Size of this descriptor in bytes
Descriptor type (string)
Manufacturer Descriptor. The text string is encoded in
UNICODE.
26h
03h
“NetChip Technology”
9.1.10 Get String Descriptor 2
Offset
Number of
Bytes
Description
Suggested Value
0
1
2
1
1
64
Size of this descriptor in bytes
Descriptor type (string)
Product Descriptor. The text string is encoded in
UNICODE.
42h
03h
“NET2272 USB
Peripheral Controller”
9.1.11 Get String Descriptor 3
Offset
Number of
Bytes
Description
Suggested Value
0
1
2
1
1
8
Size of this descriptor in bytes
Descriptor type (string)
Serial Number Descriptor. The text string is encoded in
UNICODE.
0Ah
03h
“1001”
9.1.12 Get Configuration
Offset
Number of
Bytes
Description
Suggested Value
0
1
Returns current device configuration
00h or currently selected
configuration.
9.1.13 Get Interface
Offset
Number of
Bytes
Description
Suggested Value
0
1
Returns current alternate setting for the specified
interface
00h or currently selected
interface.
______________________________________________________________________________ 81
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
9.2
NET2272 USB Peripheral Controller
Control ‘Write’ Transfers
9.2.1 Set Address
Note: The local CPU must write the new device address into the USBADDR configuration register
Offset
Number of
Description
Suggested Value
Bytes
--
0
Sets USB address of device
wValue = device address, wIndex = 0, wLength = 0
--
9.2.2 Set Configuration
Note: The local CPU must keep track of the configuration value.
Offset
Number of
Description
Bytes
Suggested Value
--
--
0
Sets the device configuration
wValue = Configuration value, wIndex = 0,
wLength = 0
9.2.3 Set Interface
Note: The local CPU must keep track of the Interface value.
Offset
Number of
Description
Bytes
Suggested Value
--
--
0
Selects alternate setting for specified interface
wValue = Alternate setting, wIndex = specified
interface, wLength = 0
9.2.4 Device Clear Feature
Note: The local CPU must keep track of the state of the Device Remote Wakeup enable.
Offset
Number of
Description
Suggested Value
Bytes
--
0
Clear the selected device feature
wValue = feature selector, wIndex = 0, wLength = 0
FS = 1 ! Device Remote Wakeup (disable)
--
9.2.5 Device Set Feature
Offset
Number of
Bytes
Description
Suggested Value
--
0
Set the selected device feature
wValue = feature selector, wLength = 0
FS = 1 ! Device Remote Wakeup (enable),
wIndex = 0
FS = 2 ! Test Mode, wIndex = specifies test mode
--
______________________________________________________________________________ 82
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
9.2.6 Endpoint Clear Feature
Note: The local CPU must clear the endpoint halt bit by writing to the Endpoint Halt bit in the EP_RSPCLR
register.
Offset
Number of
Bytes
Description
Suggested Value
--
0
Clear the selected endpoint feature
wValue = feature selector, wIndex = endpoint number,
wLength = 0
FS = 0 ! Endpoint halt (clears halt bit)
--
9.2.7 Endpoint Set Feature
Note: The local CPU must set the endpoint halt bit by writing to the Endpoint Halt bit in the EP_RSPSET register.
Offset
Number of
Bytes
Description
Suggested Value
--
0
Set the selected endpoint feature
wValue = feature selector, wIndex = endpoint number,
wLength = 0
FS = 0 ! Endpoint halt (sets halt bit)
--
______________________________________________________________________________ 83
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
10 Electrical Specifications
10.1 Absolute Maximum Ratings
Conditions that exceed the Absolute Maximum limits may destroy the device.
Symbol
VDDC, VDD25, PVDD,
AVDD
VDDIO, VDD33
VI
Parameter
2.5V Supply Voltages
Conditions
With Respect to Ground
Min
-0.5
Max
3.6
Unit
V
3.3V Supply Voltages
DC input voltage
IOUT
DC Output Current, per pin
TSTG
TAMB
VESD
Storage Temperature
Ambient temperature
ESD Rating
With Respect to Ground
3.3 V buffer
5 V Tolerant buffer
3mA Buffer
6mA Buffer
12mA Buffer
No bias
Under bias
R = 1.5K, C = 100pF
-0.5
-0.5
-0.5
-10
-20
-40
-65
-40
4.6
4.6
6.6
10
20
40
150
85
2
V
V
V
mA
mA
mA
°C
°C
KV
Min
2.2
Max
2.6
Unit
V
3.2
0.8
0.8
1.3
1.3
0
0
0.5* VDDIO
2.0
3.5
1.7
1.7
2.4
2.4
0.7
0.8
V
V
V
V
V
V
V
V
V
mA
10.2 Recommended Operating Conditions
Conditions that exceed the Operating limits may cause the device to function incorrectly.
Symbol
VDDC, VDD25, PVDD,
AVDD
VDDIO, VDD33
VN
3.3V Supply Voltages
Negative trigger voltage
VP
Positive trigger voltage
VIL
Low Level Input Voltage
VIH
High Level Input Voltage
IOL
Low Level Output Current
IOH
TA
tR
tF
tR
tF
Parameter
2.5V Supply Voltages
High Level Output Current
Operating Temperature
Input rise times
Input fall time
Input rise times
Input fall time
Conditions
3.3 V buffer
5 V tolerant buffer
3.3 V buffer
5 V tolerant buffer
3.3 V buffer
5 V tolerant buffer
3.3 V buffer
5 V tolerant buffer
3 mA buffer, (VOL = 0.4)
6 mA buffer, (VOL = 0.4)
12 mA buffer, (VOL = 0.4)
3 mA buffer,(VOH = 2.4)
6 mA buffer,(VOH = 2.4)
12 mA buffer,(VOH = 2.4)
Normal input
Normal input
Schmitt input
Schmitt input
0
0
0
0
0
VDDIO
5.5
3
6
12
-3
-6
-12
70
200
200
10
10
mA
mA
mA
mA
mA
°C
ns
ns
ms
ms
______________________________________________________________________________ 84
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
10.3 DC Specifications
10.3.1 Core DC Specifications
Operating Conditions: VDDC: 2.2-2.6V, VDDIO: 3.2-3.5V, TA = 0°C to 70°C
All typical values are at VDDC = 2.5V, VDDIO = 3.3V and TA = 25°C
10.3.1.1 Disconnected from USB
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
IVDD33
3.3V Supply Current
VDDC = 3.3V
1.4
1.6
mA
IVDD25
2.5V Supply Current
VDDIO = 2.5V
36.3
40
mA
Typ
Max
Unit
10.3.1.2 Connected to USB (High-Speed)
Symbol
Parameter
Conditions
Min
IVDD33
3.3V Supply Current
VDDC = 3.3V
3.3
3.7
mA
IVDD25
2.5V Supply Current
VDDIO = 2.5V
51.6
58
mA
Typ
Max
Unit
10.3.1.3 Active (High-Speed)
Symbol
Parameter
Conditions
Min
IVDD33
3.3V Supply Current
VDDC = 3.3V
4
4.4
mA
IVDD225
2.5V Supply Current
VDDIO = 2.5V
52.7
58
mA
Typ
Max
Unit
10.3.1.4 Connected to USB (Full-Speed)
Symbol
Parameter
Conditions
Min
IVDD33
3.3V Supply Current
VDDC = 3.3V
2.8
3.1
mA
IVDD25
2.5V Supply Current
VDDIO = 2.5V
35.3
40
mA
Typ
Max
Unit
10.3.1.5 Active (Full-Speed)
Symbol
Parameter
Conditions
Min
IVDD33
3.3V Supply Current
VDDC = 3.3V
6
6.6
mA
IVDD25
2.5V Supply Current
VDDIO = 2.5V
35.9
40
mA
Typ
Max
Unit
10.3.1.6 Suspended
Symbol
Parameter
Conditions
Min
IVDD33
3.3V Supply Current
VDDC = 3.3V
0.1*
10
uA
IVDD25
2.5V Supply Current
VDDIO = 2.5V
0.1
10
uA
* Disconnected from USB. When connected to USB, 200uA is added for the 1.5K pull-up resistor.
16-bit data bus (LD[15:0]) should not float when suspended to prevent leakage current.
______________________________________________________________________________ 85
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
10.3.2 USB Full Speed DC Specifications
Operating Conditions: VDDC: 2.2-2.6V, VDDIO: 3.2-3.5V, TA = 0°C to 70°C
All typical values are at VDDC = 2.5V, VDDIO = 3.3V and TA = 25°C
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
VIH
Input high level (driven)
Note 4
2.0
VIHZ
Input high level (floating)
Note 4
2.7
VIL
Input low level
Note 4
VDI
Differential Input Sensitivity
| (D+) - (D-) |
0.2
VCM
Differential Common Mode
Range
Includes VDI range
0.8
2.5
V
VOL
Output low level
Notes 4,5
0.0
0.3
V
VOH
Output high level (driven)
Notes 4,6
2.8
3.6
V
VSE1
Single ended one
VCRS
Output signal crossover voltage
Note 10
I/O Capacitance
Pin to GND
CIO
V
3.6
V
0.8
V
V
0.8
V
1.3
2.0
V
20
pF
Max
Unit
10.3.3 USB High Speed DC Specifications
Operating Conditions: VDDC: 2.2-2.6V, VDDIO: 3.2-3.5V, TA = 0°C to 70°C
All typical values are at VDDC = 2.5V, VDDIO = 3.3V and TA = 25°C
Symbol
Parameter
Conditions
Min
Typ
VHSSQ
High-speed squelch detection
threshold (differential signal
amplitude)
100
150
mV
VHSDSC
High-speed disconnect detection
threshold (differential signal
amplitude)
525
625
mV
High-speed differential input
signaling levels
Specified by eye patterns
VHSCM
Hip-speed data signaling common
mode voltage range
-50
500
mV
VHSOI
High-speed idle level
-10
10
mV
VHSOH
High-speed data signaling high
360
440
mV
VHSOL
High-speed data signaling low
-10
10
mV
VCHIPRJ
Chirp J level (differential voltage)
700
1100
mV
VCHIPRK
Chirp K level (differential voltage)
-900
-500
mV
20
pF
CIO
I/O Capacitance
Pin to GND
______________________________________________________________________________ 86
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
10.3.4 Local Bus DC Specifications
Operating Conditions: VDDC: 2.2-2.6V, VDDIO: 3.2-3.5V, TA = 0°C to 70°C
All typical values are at VDDC = 2.5V, VDDIO = 3.3V and TA = 25°C
Symbol
Parameter
VIH
5.0V Tolerant Input High Voltage
VIL
5.0V Tolerant Input Low Voltage
IIL
Input Leakage
0V < VIN < 5.5V
IOZ
Hi-Z State Data Line Leakage
0V < VIN < 5.5V
VOH
5.0V Tolerant Output High
Voltage
IOUT = -12mA
VOL
5.0V Tolerant Output Low
Voltage
IOUT = 12mA
0.4
V
CIN
Input Capacitance
Pin to GND
10
pF
CLK Pin Capacitance
Pin to GND
12
pF
IDSEL Pin Capacitance
Pin to GND
8
pF
CCLK
CIDSEL
Conditions
Min
Typ
Max
Unit
2.0
5.5
V
0
0.8
V
-10
10
µA
10
µA
2.4
5
V
______________________________________________________________________________ 87
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
10.4 AC Specifications
10.4.1 USB Full Speed Port AC Specifications
Operating Conditions: VDDC: 2.2-2.6V, VDDIO: 3.2-3.5V, TA = 0°C to 70°C
All typical values are at VDDC = 2.5V, VDDIO = 3.3V and TA = 25°C
Symbol
TFR
Parameter
Rise & Fall Times
Conditions
CL = 50 pF,
Min
Figure 8-1
Note 16
TFF
TFRFM
Rise/Fall time matching
(TFR/ TFF), Note
10
ZDRV
Driver Output Resistance
Steady State Drive
TFDRATHS
Waveform
Figure 8-1
Full-speed Data Rate
Typ
Max
Unit
4
20
ns
4
20
90
110
%
10
15
Ω
11.994
12
12.006
Mbs
TDJ1
Source Differential Driver Jitter to Notes 7,8,10,12
Next Transition
Figure 8-2
-2
0
2
ns
TDJ2
Source Differential Driver Jitter
for Paired Transitions
Notes 7,8,10,12
Figure 8-2
-1
0
1
ns
Source Jitter for Differential
Transition to SE0 Transition
Note 8, 11
Figure 8-3
-2
0
5
ns
TJR1
Receiver Data Jitter Tolerance to
Next Transition
Note 8
Figure 8-4
-18.5
0
18.5
ns
TJR2
Receiver Data Jitter Tolerance for
Paired Transitions
Note 8
Figure 8-4
-9
0
9
ns
Figure 8-3
160
167
175
ns
Figure 8-3
82
ns
14
ns
TFDEOP
TEOPT
Source SE0 interval of EOP
TFEOPR
Receiver SE0 interval of EOP
TFST
Width of SE0 interval during
differential transition
Note 13
10.4.2 USB High Speed Port AC Specifications
Operating Conditions: VDDC: 2.2-2.6V, VDDIO: 3.2-3.5V, TA = 0°C to 70°C
All typical values are at VDDC = 2.5V, VDDIO = 3.3V and TA = 25°C
Symbol
THSR
Parameter
Rise & Fall Times
Conditions
Note 16
THSDRV
Min
Typ
Max
500
Unit
ps
500
THSF
ZDRV
Waveform
Driver Output Resistance
Steady State Drive
High-speed Data Rate
10
479.760
Data source jitter
Specified by eye
pattern templates
Receiver jitter tolerance
Specified by eye
pattern templates
480
15
Ω
480.240
Mbs
______________________________________________________________________________ 88
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
10.4.3 USB Full Speed Port AC Waveforms
Rise Time
Fall Time
90%
CL
90%
Differential
Data Lines
10%
10%
CL
tF
tR
Full Speed: 4 to 20ns at C L = 50pF
Figure 10-1. Data Signal Rise and Fall Time
TPERIOD
Crossover
Points
Differential
Data Lines
Consecutive
Transitions
N*TPERIOD +TxJR1
Paired
Transitions
N*TPERIOD +TxJR2
Figure 10-2. Differential Data Jitter
TPERIOD
Crossover
Point
Crossover
Point Extended
Differential
Data Lines
Diff. Data to
SE0 Skew
N*TPERIOD+TFDEOP
Source EOP Width: TFEOPT
Receiver EOP Width: TFEOPR
Figure 10-3. Differential to EOP Transition Skew and EOP Width
______________________________________________________________________________ 89
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
TPERIOD
Differential
Data Lines
TJR
TJR1
TJR2
Consecutive
Transitions
N*TPERIOD +TJR1
Paired
Transitions
N*TPERIOD +TJR2
Figure 10-4. Receiver Jitter Tolerance
______________________________________________________________________________ 90
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
10.4.4 USB Port AC/DC Specification Notes
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
Measured at A plug.
Measured at A receptacle.
Measured at B receptacle.
Measured at A or B connector.
Measured with RL of 1.425KΩ to 3.6V.
Measured with RL of 14.25KΩ to GND.
Timing difference between the differential data signals.
Measured at crossover point of differential data signals.
The maximum load specification is the maximum effective capacitive load allowed that meets the target hub
VBUS droop of 330 mV.
Excluding the first transition from the Idle state.
The two transitions should be a (nominal) bit time apart.
For both transitions of differential signaling.
Must accept as valid EOP.
Single-ended capacitance of D+ or D- is the capacitance of D+/D- to all other conductors and, if present, shield
in the cable. That is, to measure the single-ended capacitance of D+, short D-, VBUS, GND, and the shield line
together and measure the capacitance of D+ to the other conductors.
For high power devices (non-hubs) when enabled for remote wakeup.
Measured from 10% to 90% of the data signal.
______________________________________________________________________________ 91
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
10.4.5 Local Bus Non-Multiplexed Read
Operating Conditions: VDDC: 2.2-2.6V, VDDIO: 3.2-3.5V, TA = 0°C to 70°C, Output Load = 25pF
NAME
DESCRIPTION
T4
T5
T6
MIN
Address setup to read enable
Address hold from end of read enable
Data access time from LA valid or read enable
asserted (1), whichever is later
Data tri-state time from end of read enable
Recovery Time to next read (2)
Recovery Time to next write
Read Cycle Time
T7
T8A
T8B
T16
MAX
UNIT
18
ns
ns
ns
-1
-2
2
19
19
35
11
ns
ns
ns
ns
(1) Read enable is the occurrence of both CS# and IOR#.
(2) Since reading and writing to EP_DATA cause EP_AVAIL and EP_TRANSFER to change values, it is
necessary to increase the recovery time to 37 nsec between a read or write to EP_DATA and a read from
EP_AVAIL or EP_TRANSFER.
0ns
25ns
50ns
75ns
100ns
T5
LA[4:0]
T5
A0
A1
T4
T16
T4
T8A
CS# & IOR#
T6
LD[15:0]
T7
D0
T6
T7
D1
______________________________________________________________________________ 92
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
10.4.6 Local Bus Multiplexed Read
Operating Conditions: VDDC: 2.2-2.6V, VDDIO: 3.2-3.5V, TA = 0°C to 70°C, Output Load = 25pF
NAME
DESCRIPTION
T1
T2
T3
T19
T6
T7
T8A
T8B
T9
T16
MIN
Address setup to falling edge of ALE
Address hold from falling edge of ALE
ALE Width
ALE falling edge to read enable
Data access time from read enable (1)
Data tri-state time from end of read enable
Recovery Time to next read (2)
Recovery Time to next write
Recovery Time to next ALE
Read Cycle Time
MAX
UNIT
18
11
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
5
1
5
1
2
19
19
5
35
(1) Read enable is the occurrence of both CS# and IOR#.
(2) Since reading and writing to EP_DATA cause EP_AVAIL and EP_TRANSFER to change values, it is
necessary to increase the recovery time to 37 nsec between a read or write to EP_DATA and a read from
EP_AVAIL or EP_TRANSFER.
0ns
25ns
50ns
T3
75ns
T3
T1
T9
T1
ALE
T19
T16
T19
T8A
CS# & IOR#
T6
T2
LD[15:0]
A0
T7
D0
T2
A1
T6
T7
D1
______________________________________________________________________________ 93
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
10.4.7 Local Bus Non-Multiplexed Write
Operating Conditions: VDDC: 2.2-2.6V, VDDIO: 3.2-3.5V, TA = 0°C to 70°C, Output Load = 25pF
NAME
DESCRIPTION
T10
T11
T12
T13
T14
T15A
T15B
MIN
Address setup to end of write enable
Address hold from end of write enable
Write enable width (1)
Data setup to end of write enable
Data hold time from end of write enable
Recovery Time to next write
Recovery Time to next read (2)
MAX
UNIT
5
0
5
5
0
28
52
ns
ns
ns
ns
ns
ns
ns
(1) Write enable is the occurrence of both CS# and IOW#.
(2) Since reading and writing to EP_DATA cause EP_AVAIL and EP_TRANSFER to change values, it is
necessary to increase the recovery time to 70 nsec between a read or write to EP_DATA and a read from
EP_AVAIL or EP_TRANSFER.
0ns
10ns
20ns
30ns
40ns
50ns
T11
LA[4:0]
60n
T11
A0
A1
T10
T13
T12
T10
T13
T12
T15A
CS# & IOW#
T14
LD[15:0]
D0
T14
D1
______________________________________________________________________________ 94
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
10.4.8 Local Bus Multiplexed Write
Operating Conditions: VDDC: 2.2-2.6V, VDDIO: 3.2-3.5V, TA = 0°C to 70°C, Output Load = 25pF
NAME
T1
T2
T3
T19
T12
T13
T14
T15A
T15B
DESCRIPTION
MIN
Address setup to falling edge of ALE
Address hold from falling edge of ALE
ALE Width
ALE falling edge to write enable
Write enable width (1)
Data setup to end of write enable
Data hold time from end of write enable
Recovery Time to next write
Recovery Time to next read (2)
MAX
UNIT
5
1
5
1
5
5
0
28
52
ns
ns
ns
ns
ns
ns
ns
ns
ns
(1) Write enable is the occurrence of both CS# and IOW#.
(2) Since reading and writing to EP_DATA cause EP_AVAIL and EP_TRANSFER to change values, it is
necessary to increase the recovery time to 70 nsec between a read or write to EP_DATA and a read from
EP_AVAIL or EP_TRANSFER.
0ns
10ns
20ns
30ns
40ns
T1
T3
50ns
60ns
T1
T3
ALE
T12
T19
T19
T13
T15A
T12
T13
CS# & IOW#
T2
LD[15:0]
A0
T14
D0
T2
A1
T14
D1
______________________________________________________________________________ 95
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
10.4.9 Local Bus DMA Read; Slow Mode
Operating Conditions: VDDC: 2.2-2.6V, VDDIO: 3.2-3.5V, TA = 0°C to 70°C, Output Load = 25pF
NAME
T20
T21
T22
T23
T24
T25
DESCRIPTION
MIN
TYP
MAX
UNIT
25
16
50
50
2
10
15
60
68
16
12
25
ns
ns
ns
ns
ns
ns
Read enable true to DREQ false (2)
Read enable false to DREQ true
Data access time from read enable (1)
Data tri-state time from end of read enable
Width of EOT# pulse (3)
DREQ false to DREQ true
(1) For non-split DMA mode, read enable is the occurrence of DACK# and optionally, IOR#. For split DMA mode,
read enable is the occurrence of DACK# and optionally, DMARD#.
(2) The minimum value is only guaranteed if the DMA Request Enable bit in the DMAREQ register is set.
(3) EOT#, DACK#, and optionally, IOR# or DMARD# must all be true for at least T24 for proper recognition of the
EOT# pulse.
(4) A recovery time of 2 nsec is required between the de-assertion of DMA read enable and the assertion of an I/O
read enable.
0ns
50ns
100ns
T20
T21
T25
150ns
200ns
T20
DREQ
DACK#
IOR# (Optional)
LD[15:0]
T22
D0
T23
T22
T23
D1
T24
EOT# (Optional)
______________________________________________________________________________ 96
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
10.4.10
Local Bus DMA Read; Fast Mode
Operating Conditions: VDDC: 2.2-2.6V, VDDIO: 3.2-3.5V, TA = 0°C to 70°C, Output Load = 25pF
NAME
T20
T21
T22
T23
T24
T25
DESCRIPTION
MIN
Read enable true to DREQ false (2)
Read enable false to DREQ true
Data access time from read enable (1)
Data tri-state time from end of read enable
Width of EOT# pulse (3)
DREQ false to DREQ true
TYP
4
4
35
2
10
15
35
MAX
UNIT
19
45
16
12
ns
ns
ns
ns
ns
ns
(1) For non-split DMA mode, read enable is the occurrence of DACK# and optionally, IOR#. For split DMA mode,
read enable is the occurrence of DACK# and optionally, DMARD#.
(2) The minimum value is only guaranteed if the DMA Request Enable bit in the DMAREQ register is set.
(3) EOT#, DACK#, and optionally, IOR# or DMARD# must all be true for at least T24 for proper recognition of the
EOT# pulse.
(4) A recovery time of 2 nsec is required between the de-assertion of DMA read enable and the assertion of an I/O
read enable.
0ns
50ns
100ns
T20
T25
T21
150ns
200ns
T20
DREQ
DACK#
IOR# (Optional)
T22
LD[15:0]
T23
T22
D0
T23
D1
T24
EOT# (Optional)
______________________________________________________________________________ 97
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
10.4.11
Local Bus DMA Read; Burst Mode
Operating Conditions: VDDC: 2.2-2.6V, VDDIO: 3.2-3.5V, TA = 0°C to 70°C, Output Load = 25pF
NAME
T17
T18
T20
T22
T23
T24
DESCRIPTION
MIN
DMA Read Cycle time
DMA Read Recovery time
Read enable true to DREQ false
Data access time from read enable (1)
Data tri-state time from end of read enable
Width of EOT# pulse (3)
TYP
MAX
35
19
4
ns
ns
ns
ns
ns
ns
20
16
12
2
10
UNIT
(1) For non-split DMA mode, read enable is the occurrence of DACK# and optionally, IOR#. For split DMA mode,
read enable is the occurrence of DACK# and optionally, DMARD#.
(3) EOT#, DACK#, and optionally, IOR# or DMARD# must all be true for at least T24 for proper recognition of the
EOT# pulse.
(4) A recovery time of 2 nsec is required between the de-assertion of DMA read enable and the assertion of an I/O
read enable.
0ns
25ns
50ns
75ns
100ns
125ns
1
T20
DREQ
T17
T17
T18
T18
DACK#
IOR# (Optional)
T22
LD[15:0]
T23
D0
T22
T23
D1
T22
T23
D2
T24
EOT# (Optional)
______________________________________________________________________________ 98
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
10.4.12
Local Bus DMA Write; Slow Mode
Operating Conditions: VDDC: 2.2-2.6V, VDDIO: 3.2-3.5V, TA = 0°C to 70°C, Output Load = 25pF
NAME
T20
T21
T25
T26
T27
T28
T29
DESCRIPTION
MIN
TYP
MAX
UNIT
17
23
15
5
5
0
5
50
50
25
60
72
ns
ns
ns
ns
ns
ns
ns
Write enable true to DREQ false (2)
Write enable false to DREQ true
DREQ false to DREQ true
Write enable width (1)
Data setup to end of write enable
Data hold time from end of write enable
Width of EOT# pulse (3)
(1) For non-split DMA mode, write enable is the occurrence of DACK# and optionally, IOW#. For split DMA
mode, write enable is the occurrence of DACK# and optionally, DMAWR#.
(2) The minimum value is only guaranteed if the DMA Request Enable bit in the DMAREQ register is set.
(3) EOT#, DACK#, and optionally, IOW# or DMAWR# must all be true for at least T29 for proper recognition of
the EOT# pulse.
0ns
50ns
100ns
150ns
200ns
T21
T20
T25
T20
DREQ
T26
T27
T26
T27
DACK#
IOW# (Optional)
T28
LD[15:0]
D0
T28
D1
T29
EOT# (Optional)
______________________________________________________________________________ 99
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
10.4.13
Local Bus DMA Write; Fast Mode
Operating Conditions: VDDC: 2.2-2.6V, VDDIO: 3.2-3.5V, TA = 0°C to 70°C, Output Load = 25pF
NAME
T20
T21
T25
T26
T27
T28
T29
DESCRIPTION
MIN
Write enable true to DREQ false (2)
Write enable false to DREQ true
DREQ false to DREQ true
Write enable width (1)
Data setup to end of write enable
Data hold time from end of write enable
Width of EOT# pulse (3)
4
16
15
5
5
0
5
TYP
45
40
MAX
UNIT
19
55
ns
ns
ns
ns
ns
ns
ns
(1) For non-split DMA mode, write enable is the occurrence of DACK# and optionally, IOW#. For split DMA
mode, write enable is the occurrence of DACK# and optionally, DMAWR#.
(2) The minimum value is only guaranteed if the DMA Request Enable bit in the DMAREQ register is set.
(3) EOT#, DACK#, and optionally, IOW# or DMAWR# must all be true for at least T29 for proper recognition of
the EOT# pulse.
0ns
50ns
100ns
150ns
200ns
T20
T25
T21
T20
DREQ
T26
T27
T26
T27
T28
T28
DACK#
IOW# (Optional)
LD[15:0]
D0
D1
T29
EOT# (Optional)
______________________________________________________________________________ 100
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
10.4.14
Local Bus DMA Write; Burst Mode
Operating Conditions: VDDC: 2.2-2.6V, VDDIO: 3.2-3.5V, TA = 0°C to 70°C, Output Load = 25pF
NAME
T20
T26
T27
T28
T29
T30
DESCRIPTION
MIN
Write enable true to DREQ false
Write enable width (1)
Data setup to end of write enable
Data hold time from end of write enable
Width of EOT# pulse (3)
DMA Write Recovery
TYP
MAX
UNIT
20
ns
ns
ns
ns
ns
ns
4
5
5
0
5
28
(1) For non-split DMA mode, write enable is the occurrence of DACK# and optionally, IOW#. For split DMA
mode, write enable is the occurrence of DACK# and optionally, DMAWR#.
(3) EOT#, DACK#, and optionally, IOW# or DMAWR# must all be true for at least T29 for proper recognition of
the EOT# pulse.
0ns
25ns
50ns
75ns
100ns
125ns
T20
DREQ
T27
T26
T27
T26
T30
T27
T26
T30
DACK#
IOW# (Optional)
T28
LD[15:0]
D0
T28
D1
T28
D2
T29
EOT# (Optional)
______________________________________________________________________________ 101
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
Specification
NET2272 USB Peripheral Controller
11 Mechanical Drawing
64-PIN PLASTIC TQFP (10x10)
A
B
detail of lead end
33
48
49
32
S
D
P
C
R
Q
64
17
1
F
G
L
16
H
J
I
ITEM
M
K
M
P
N
L
NOTE
Each lead centerline is located within 0.13 mm of its
true position (T.P.) at maximum material condition.
MILLIMETERS
INCHES
0.472± 0.009
0.008
0.394± 0.008
0.009
0.394± 0.008
0.009
0.472± 0.009
0.008
A
12.0±0.2
B
10.0±0.2
C
10.0±0.2
D
12.0±0.2
F
1.25
0.049
G
1.25
0.049
H
0.22± 0.055
0.045
0.009±0.002
I
0.10
0.004
J
0.5 (T.P.)
0.020 (T.P.)
K
1.0±0.2
L
0.5±0.2
0.039± 0.009
0.008
0.020± 0.008
0.009
M
0.145± 0.055
0.045
0.006±0.002
N
0.10
0.004
P
1.0±0.1
0.039± 0.005
0.004
Q
0.1±0.05
0.004±0.002
R
3°± 7°
3°
3°± 7°
3°
S
1.27 MAX
0.050 MAX
S64GB-50-9EU-1
______________________________________________________________________________ 102
 NetChip Technology, Inc., 2003
Patent Pending
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490 FAX (650) 526-1494
http://www.netchip.com
Rev 1.2, October 15, 2003
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