Texas Instruments TMS320C6000 DSP Guide

TMS320C6000NetworkDeveloper'sKit
(NDK) Support Package Ethernet
Driver Design Guide
Literature Number: SPRUFP2
January 2009

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iii
This is a draft version printed from file: pref.fm on 1/5/09
Preface
About This Guide
This document describes the design of the Ethernet driver architecture
introduced in NDK 2.0. This design differs from that in previous versions
of NDK. All Ethernet drivers packaged as a part of the Network
Developer's Kit (NDK) Support Package in NDK 2.0 follow the generic
architecture described in this document.
Important Note:
❏This document covers only the Ethernet driver architecture. The
serial driver is no longer supported as of NDK 2.0. For serial driver
information, see documentation from earlier releases of the NDK.
❏The setup and installation steps for each NDK Support Package
(NSP) are provided in the Release Notes provided with that NSP.
Intended Audience
This document is intended for writers of Ethernet mini-drivers. This
document assumes you have knowledge of Ethernet concepts.
Related Documents The following books describe the TMS320C6x devices and related
support tools. To obtain a copy of any of these TI documents, call the
Texas Instruments Literature Response Center at [phone]. When
ordering, please identify the book by its title and literature number. Many
of these documents can be found on the Internet at http://www.ti.com.
❏SPRU189 - TMS320C6000 CPU and Instruction Set Reference
Guide. Describes the CPU architecture, pipeline, instruction set, and
interrupts for the TMS320C6000 DSPs.
❏SPRU190 - TMS320C6000 DSP Peripherals Overview Reference
Guide. Provides an overview and briefly describes peripherals
available on the TMS320C6000 family of DSPs.
❏SPRU197 - TMS320C6000 Technical Brief. Provides an introduction
to the TMS320C62x and TMS320C67x digital signal processors
(DSPs) of the TMS320C6000 DSP family. Describes the CPU
architecture, peripherals, development tools, and third-party support
for the C62x and C67x DSPs.

iv
Notational Conventions
❏SPRU198 - TMS320C6000 Programmer's Guide. Reference for
programming the TMS320C6000 digital signal processors (DSPs).
Before you use this manual, you should install your code generation
and debugging tools. Includes a brief description of the C6000 DSP
architecture and code development flow, includes C code examples
and discusses optimization methods for the C code, describes the
structure of assembly code and includes examples and discusses
optimizations for the assembly code, and describes programming
considerations for the C64x DSP.
❏SPRU509 - Code Composer Studio Development Tools v3.3 Getting
Started Guide introduces some of the basic features and
functionalities in Code Composer Studio to enable you to create and
build simple projects.
❏SPRU523 - TMS320C6000 Network Developer's Kit (NDK) Software
User's Guide. Describes how to use the NDK libraries, how to
develop networking applications on TMS320C6000 platforms, and
ways to tune the NDK to fit a particular software environment.
❏SPRU524 - TMS320C6000 Network Developer's Kit (NDK) Software
Programmer's Reference Guide. Describes the various API functions
provided by the stack libraries, including the low level hardware APIs.
Notational Conventions
This document uses the following conventions:
❏Program listings, program examples, and interactive displays are
shown in a mono-spaced font. Examples use bold for emphasis,
and interactive displays use bold to distinguish commands that you
enter from items that the system displays (such as prompts,
command output, error messages, etc.).
❏Square brackets ( [ and ] ) identify an optional parameter. If you use
an optional parameter, you specify the information within the
brackets. Unless the square brackets are in a bold typeface, do not
enter the brackets themselves.
Trademarks The Texas Instruments logo and Texas Instruments are registered
trademarks of Texas Instruments. Trademarks of Texas Instruments
include: TI, Code Composer, Code Composer Studio, DSP/BIOS,
TMS320, TMS320C6000, TMS320C64x, TMS320DM644x, and
TMS320C64x+.
All other brand, product names, and service names are trademarks or
registered trademarks of their respective companies or organizations.
January 5, 2009

v
This is a draft version printed from file: ndk_spTOC.fm on 1/5/09
Contents
1 Architecture Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1
This chapter provides an overview of the terminology and components involved in the Network De-
veloper's Kit Support Package (NSP) Ethernet driver. It also describes the architecture of such
drivers.
1.1 Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2
1.2 Ethernet Driver Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3
1.2.1 NIMU-Specific Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4
1.2.2 Ethernet Mini-Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4
1.2.3 Generic EMAC/MDIO Chip Support Library. . . . . . . . . . . . . . . . . . . . . . . . . .1-5
1.3 Flow Charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-6
1.4 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-8
1.4.1 Network Control (NETCTRL) Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-8
1.4.2 Stack Event (STKEVENT) Object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-8
1.4.3 Packet Buffer (PBM) Object. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-8
1.4.4 NDK Interrupt Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-9
1.4.5 Data Alignment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-9
1.5 API Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-10
2 NIMU Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1
This chapter describes Network Interface Management Unit (NIMU) layer API.
2.1 Overview of the NIMU Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2
2.2 NIMU APIs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2
3 Ethernet Mini-Driver Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1
This chapter describes Ethernet mini-driver layer interface.
3.1 Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2
3.2 Data Structures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2
3.3 Ethernet Mini-Driver APIs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-4
3.3.1 HwPktInit — Initialize Packet Driver Environment . . . . . . . . . . . . . . . . . . . . .3-5
3.3.2 HwPktOpen — Open Ethernet Device Instance. . . . . . . . . . . . . . . . . . . . . . .3-5
3.3.3 HwPktClose — Close Ethernet Device and Disable Interrupts . . . . . . . . . . .3-5
3.3.4 HwPktSetRx — Configure the Ethernet Receive Filter Settings . . . . . . . . . .3-6
3.3.5 HwPktIoctl — Execute Driver-Specific IOCTL Commands . . . . . . . . . . . . . .3-6
3.3.6 HwPktTxNext — Transmit Next Buffer in the Transmit Queue . . . . . . . . . . .3-6
3.3.7 _HwPktPoll — Mini-Driver Polling Function . . . . . . . . . . . . . . . . . . . . . . . . . .3-7
3.4 Configuration Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-7

Contents
vi
4 Generic EMAC/MDIO CSL Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
This chapter describes the EMAC/MDIO CSL layer interface.
4.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
4.2 CSL Data Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
4.3 EMAC APIs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
4.4 Callback Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
4.4.1 pfcbGetPacket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
4.4.2 pfcbFreePacket. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
4.4.3 pfcbRxPacket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
4.4.4 pfcbStatus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
4.4.5 pfcbStatistics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

1-1
Chapter 1
Architecture Overview
This chapter provides an overview of the terminology and components
involved in the Network Developer's Kit Support Package (NSP) Ethernet
driver. It also describes the architecture of such drivers.
1.1 Acronyms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–2
1.2 Ethernet Driver Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–3
1.3 Flow Charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–6
1.4 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–8
1.5 API Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–10
Topic Page

Acronyms
1-2
1.1 Acronyms
The following acronyms are used in this document:
Table 1–1 Acronyms
Acronym Description
API Application Programming Interface
BD Buffer Descriptor
CSL Chip Support Library
DSP Digital Signal Processor
EMAC Ethernet Medium Access Protocol
LL Low Level Packet Driver
MDIO Management Data Input/Output Interface
NDK Network Developer's Kit
NIMU Network Interface Management Unit
NSP NDK Support Package
OS AL Operating Systems Abstraction Layer
Rx Receive Operation
SGMII Serial Gigabit Media Independent Interface
Tx Transmit Operation

Ethernet Driver Architecture
Architecture Overview 1-3
1.2 Ethernet Driver Architecture
The following diagram shows the architecture of the Ethernet driver
design in the NDK 2.0 Support Package (NSP).
This new NSP Ethernet driver architecture consists of the following
components:
❏NIMU-specific layer, which acts as the interface between the NDK
stack and the Ethernet driver. See Section 1.2.1.
❏Ethernet mini-driver, which manages the EMAC configuration
using the CSL. Also manages DSP interrupts and memory allocation
for packet buffers in buffer descriptors using the NDKOperating Systems
Abstraction Layer (OS AL). See Section 1.2.2.
❏Generic EMAC/MDIO Chip Support Library (CSL), which contains
the generic APIs and data structures needed to control and configure
EMAC/MDIO peripherals. Also manages buffer descriptors and
interrupt service routines. See Section 1.2.3.
NDK
NSP Ethernet
Driver
Hardware
Software
NDK Core Stack
NIMU NDK Core Layer
NIMU-specific layer
Ethernet PHY(s)
Ethernet mini-driver
Generic EMAC/MDIO Chip Support
Library (CSL)

Ethernet Driver Architecture
1-4
The NIMU-specific layer in previous versions of the NDK was generic
enough to be ported to different platforms with ease. However, the mini-
driver was not easily portable and had to be rewritten from scratch every
time it had to be ported to a new platform. This led to different flavors of
the Ethernet device drivers for different platforms—thus increasing the
development, maintenance, and debugging effort.
To overcome the limitations of this architecture, the architecture of
Ethernet drivers in the NSPs have been reorganized to optimize for a
better development and debugging experience. The Generic
EMAC/MDIO Chip Support Library (CSL) component is new; it has been
split apart from the Ethernet mini-driver component to better isolate
portions that commonly require changes when porting.
1.2.1 NIMU-Specific Layer
The Network Interface Management Unit (NIMU) specific layer acts as
the interface between the Ethernet driver and the NDK core stack. It
provides an implementation for the APIs defined by the NIMU
specification for this EMAC device. These APIs let the NDK core stack
control and configure the EMAC device at runtime and transmit packets.
They also enable the driver to hand any received packets back to the
stack.
This layer is fairly generic and doesn't change between different
platforms.
This layer's functionality and role are the same as in versions of NDK
prior to v2.0.
1.2.2 Ethernet Mini-Driver
This layer is responsible for setting up parameters for EMAC and MDIO
configuration according to system needs. It uses APIs and data
structures exported by the underlying Chip Support Library (CSL) layer.
It is also responsible for setting up EMAC interrupts into the DSP using
data structures and APIs exposed by the "Interrupt Manager Wrapper" in
the NDK OS AL.
This layer acts as the sole memory manager in the Ethernet driver. That
is, it handles all memory allocations, initializations, and frees of packet
buffers for use in the buffer descriptors (BDs) in the Transmit (Tx) and
Receive (Tx) paths. For memory management, it again uses the data
structures and APIs defined by the NDK OS AL.

Ethernet Driver Architecture
Architecture Overview 1-5
For the most part, the mini-driver invokes CSL APIs for setup, Tx, and
interrupt service operations. The CSL layer, however, can also invoke the
mini-driver layer. The CSL layer can invoke the mini-driver registered
callback functions (set up during EMAC_open) for updating statistics and
reporting errors. On receiving a packet, it can hand over the packet to be
passed up the stack or for memory allocation/free of buffers in BDs.
This layer is OS agnostic, since it uses the NDK OS AL for all memory
and interrupt management operations. However, this layer is device-
dependent since the EMAC peripheral setup requires knowledge of the
capabilities of EMAC on this platform/device and will have to be
customized for each platform and for application needs. So, this layer
needs to be ported and customized from one platform to another.
1.2.3 Generic EMAC/MDIO Chip Support Library
This layer enables the generic driver architecture by doing the following:
❏EMAC APIs. It defines the data structures and interfaces (APIs)
required to configure and use EMAC for transmit and receive
operations.
❏MDIO and SGMII APIs. It exposes APIs for managing the PHY-
related (physical layer) configuration through the MDIO and SGMII (if
the PHY is capable of gigabit speed) modules.
❏BD logic. It implements the basic logic for CPPI Buffer Descriptor
management (setup, enqueuing, and dequeuing operations).
❏ISR logic. It contains the central logic for interrupt service routines.
However, it uses the mini-driver's registered callback functions to
report packet reception, statistics, errors, and obtaining or freeing a
buffer for filling up a BD.
This layer is largely generic and doesn't vary much from platform to
platform unless the EMAC capabilities change a whole lot. For example,
the CSL for an EMAC peripheral connecting to a PHY switch would be
very different from an EMAC that connects to a single PHY port. This
layer is easily portable to different devices with similar capabilities.

Flow Charts
1-6
1.3 Flow Charts
The transmission path for Ethernet packets is as follows:
User Application
send/sendto socket API
NIMUSendPacket
NDK StackProcessing
(L4–TCP/UDP/RAWandIP)
Allocate Packet, Copy Data Buff er; Add
headers and if needed fragment packets
Device Driver’s registered “send”callback
function
EmacSend(nimu_eth.c)
Is link up andTransmitter ready?
(TxFree is 1?)
HwPktTxNext
Yes
No
Just return for
now. When link
ready packet will
be dequeued by
driver and sent
out
Any pending packet in Tx
Queue (PBMQ_tx)?
Yes
No
No pending packets.
Set TxFree to 1 and
return.
Enqueuein Tx Queue, PBMQ_tx;
Return
Dequeue packet from device
PBMQ_tx.Get anempty
EMAC_pkt f rom TxQueue and
fill inpacket details.
EMAC_sendPacket
(Validate Emac_Pkt structure f ields:- flags,
buffer offset, length)
HwTxInt / HwInt
(Tx Interrupt Service Routine)
Tx Completed. EMAC raises TxCP interrupt
Emac_TxServiceCheck
IsHostInterrupt?
Is StatPending Interrupt?
Is v alidTxCP interrupt
on this channel?
emacDequeueTx
FreePacket(pfcbFreePacket)
(Driver registered callback
function to free packet buffer
that was successfully sent out)
emacEnqueueTx
(Enqueue packet in EMAC BDs and start
EMAC transmitter if not running by setting
the TxnHDP to the app. BD )
Any more pending
packets forTx
in waitQ?
Yes
No
No
Return
Return
No
No
Yes
StatisticsUpdate
(pfcbStatistics)
(Driver registered Stats
update function
notified)
StatusUpdate
(pfcbStatus)
(Driver registered
Status update function
notified toindicate error
/ status change)
Yes
Yes
Return
Return
Return

Flow Charts
Architecture Overview 1-7
The receive path for Ethernet packets is as follows:
HwRxInt / HwInt (Rx Interrupt Service Routine)
EMAC_RxServiceCheck
RxPacket(pfcbRxPacket)
(Driver registered Packet Receive Handler)
Enqueue in device Rx Queue (PBMQ_rx)
Notify Stack of pending RxEvent
NIMUPacketService
Device Registered “pkt_serv ice” callback
function
Emac_PktService
Any pending packet in Rx
Queue (PBMQ_rx)?
DequeuePacket
NIMUReceivePacket
IPRxPacket/LLIRxPacket/pppoeInput/
IPv6RxPacket
EthernetPacketReceived
by EMACHw. DSP
Interrupt Raised forEMAC
Yes
Yes
Return;
Any morepackets?
NDK Stack Processing ÆSocket
APIs
User Application
No
Return
IsHostInterrupt?
Is Stat Pending Interrupt?
Is valid Rx interrupt on
this channel?
No
No
StatisticsUpdate
(pfcbStatistics)
(Driver registered Stats
update f unction
notified)
Yes
Yes
StatusUpdate
(pfcbStatus)
(Driver registered
Status update f unction
notif ied to indicate error
/ status change)
Yes
Return
Return
Return
emacDequeueRx
(Validate Packet f lags and buf fer len; Handov er
packet to driver; )
(If validBD obtained from RxPacket return,
enqueue it and if need be start Receiver by
settingRxnHDP)
Return a new
Emac_Pkttype
packet buff er
to replenish BD
Any Pending Ethernet
Events?
NetScheduler
(wait for any HWI (Eth / Serial) / Timerevents
using SEM)
No
StackRx EventSet
(Post SEMto indicateEthHWI)

Background
1-8
1.4 Background
To port NDK Support Package device drivers, you should be familiar with
the following constructs and concepts.
1.4.1 Network Control (NETCTRL) Module
The Network Control Module (NETCTRL) is at the center of the NDK and
controls the interface of the HAL device drivers to the internal stack
functions.
The NETCTRL module and its related APIs are described in both the
TMS320C6000 Network Developer's Kit (NDK) Software Programmer's
Reference Guide (SPRU524) and the TMS320C6000 Network
Developer's Kit (NDK) Software User's Guide (SPRU523). To write
device drivers, you must be familiar with NETCTRL. The description
given in the TMS320C6000 Network Developer's Kit (NDK) Software
User's Guide (SPRU523) is more appropriate for device driver work.
1.4.2 Stack Event (STKEVENT) Object
The STKEVENT object is a central component in the low-level
architecture. It ties the HAL layer to the scheduler thread in the network
control module (NETCTRL). The network scheduler thread waits on
events from various device drivers in the system, including the Ethernet,
serial, and timer drivers.
Device drivers use the STKEVENT object to inform the scheduler that an
event has occurred. The STKEVENT object and its related API are
described in the TMS320C6000 Network Developer's Kit (NDK) Software
Programmer's Reference Guide (SPRU524). Device driver writers need
to be familiar with STKEVENT.
1.4.3 Packet Buffer (PBM) Object
The PBM object is a packet buffer that is sourced and managed by the
Packet Buffer Manager (PBM). The PBM is part of the OS adaptation
layer (OS AL). It provides packet buffers for all packet-based devices in
the system. Therefore, the serial port and Ethernet drivers both make use
of this module.
The PBM module in the NDK OS AL manages packet buffers up to 3 KB
in size. Any packet buffer allocation larger than 3 KB is managed by the
Jumbo Packet Buffer Manager (Jumbo PBM). A default Jumbo PBM

Background
Architecture Overview 1-9
implementation is provided in NDK OS AL; this implementation might
need customization according to the application needs and system's
memory constraints.
The PBM object, its related API, and the Jumbo PBM API are described
in the TMS320C6000 Network Developer's Kit (NDK) Software
Programmer's Reference Guide (SPRU524). The TMS320C6000
Network Developer's Kit (NDK) Software User's Guide (SPRU523) also
includes a section on adapting the PBM to a particular included software.
1.4.4 NDK Interrupt Manager
The NDK Interrupt Manager is a module in the NDK OS AL that abstracts
out the OS (BIOS) specific APIs and data structures required for interrupt
configuration and management. It exposes a simple interface to the
driver writer to configure EMAC interrupts into the DSP core. Interrupt
Setup (IntSetup) Object is a data structure defined by this module.
Depending on the system specification, there can be a single or multiple
system event/interrupt numbers defined for the EMAC module's Transmit
(Tx) and Receive (Rx) events. Also based on the system specification,
one could register a single Interrupt Service Routine (ISR) for both Tx and
Rx events or register separate ISRs for each event.
The following NDK Interrupt Manager APIs can be used by the Ethernet
driver in setting up the interrupts:
❏Interrupt_add
❏Interrupt_delete
❏Interrupt_enable
❏Interrupt_disable
Please see the sample Ethernet driver code packaged as the NDK
Support Package (NSP) for any C64x+ device for an illustration of
interrupt configuration using NDK Interrupt Manager APIs. The NDK
Interrupt Manager, along with its related API and data structures, are
described in the TMS320C6000 Network Developer's Kit (NDK) Software
Programmer's Reference Guide (SPRU524).
1.4.5 Data Alignment
The NDK libraries have been built with the assumption that the IP header
in a data packet is 16-bit aligned. In other words, the first byte of the IP
packet (the version/length field) must start on an even 16-bit boundary.
In any fixed-length header protocol, this requirement can be met by

API Overview
1-10
backing off any odd byte header size, and adding it to the header padding
specified to the stack. For Ethernet and peer-to-peer protocol (PPP), the
only requirement is that the Ethernet or PPP packet not start on an odd
byte boundary.
In addition, some drivers in the NDK are set up to have a 22-byte header.
This is the header size of a PPPoE packet when sent using a 14-byte
Ethernet header. When all arriving packets use the 22-byte header, it
guarantees that they can be routed to any egress device with a header
requirement up to that size. For Ethernet operation, this requires that a
packet has 8 bytes of pre-pad to make its total header size 22 bytes.
The value of this pre-pad is #defined as PKT_PREPAD in the Ethernet
driver include files.
1.5 API Overview
The various APIs exposed by the three main layers—the NIMU-specific
layer, mini-driver, and generic EMAC/MDIO CSL layer—can be classified
based on their functionality into the following categories:
❏Initialization and Shutdown APIs. These APIs are called during
Ethernet device start up to initialize the EMAC environment or during
shutdown to bring down the Ethernet controller and its subsystems.
❏Configuration APIs. These APIs are called to get/set the EMAC
configuration. The configuration APIs are generally useful in setting
the following parameters:
■multicast configuration
■receive filters on the Ethernet device
❏Transmit APIs. These APIs provide a well-defined interface for the
NDK stack to pass down any available Ethernet packets onto the wire
using the Ethernet driver.
❏Receive APIs. These APIs provide a well-defined interface for the
driver to pass up an Ethernet packet to the NDK stack and into an
application.
❏Polling APIs. These APIs provide an interface for the NDK core
stack to monitor the status of the Ethernet link on a periodic basis and
to perform any necessary configuration of the EMAC depending on a
change of state, if any.

API Overview
Architecture Overview 1-11
The following table groups the APIs defined by each of the Ethernet
driver layers under one of these five categories.
The following chapters discuss each of the layers and APIs in detail.
Table 1-2. API Mapping between the Ethernet driver layers
API Category NIMU Layer Mini-Driver Layer CSL Layer
Initialization EmacInit HwPktInit --none--
EmacStart HwPktOpen EMAC_open /
MDIO_open
Shutdown EmacStop HwPktClose, HwPktShutdown EMAC_close /
MDIO_close
Configuration Emacioctl HwPktSetRx EMAC_setReceiveFilter,
EMAC_getReceiveFilter,
EMAC_setMulticast,
EMAC_getStatus,
EMAC_getStatistics,
EMAC_enumerate
Transmit EmacSend HwPktTxNext EMAC_sendPacket,
EMAC_TxServiceCheck
(Tx ISR)
Receive EmacPktService HwInt / HwRxInt
(depends on whether the EMAC has
separate system events mapped into
DSP for Rx/Tx or just one for both)
EMAC_RxServiceCheck
(Rx ISR)
Polling EmacPoll _HwPktPoll EMAC_TimerTick,
MDIO_timerTick,
MDIO_getStatus

1-12

2-1
Chapter 2
NIMU Layer
This chapter describes Network Interface Management Unit (NIMU) layer
API.
2.1 Overview of the NIMU Layer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–2
2.2 NIMU APIs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–2
Topic Page

Overview of the NIMU Layer
2-2
2.1 Overview of the NIMU Layer
The Network Interface Management Unit (NIMU) layer interfaces with the
NDK core stack. It enables the stack to control the device at runtime. This
layer is platform-independent and is easily portable across various
platforms.
2.2 NIMU APIs
Driver writers need to implement APIs as follows to make their driver
NIMU-compliant:
1) Register a driver Init callback function with the core NDK NIMU layer
by populating the function in the NIMUDeviceTable.
2) Allocate and initialize the NETIF_DEVICE structure for this device
with the appropriate parameters and callback functions defined for
the following NIMU-defined APIs:
■start
■stop
■poll
■send
■pkt_service
■ioctl
■add_header
3) Invoke the NIMURegister API to register this device with the NDK
core's NIMU layer for further management.
4) Finally, implement all the callback functions as per the NIMU
architecture guidelines and the API descriptions described in
"Network Interface Management Unit" section of the TMS320C6000
Network Developer's Kit (NDK) Software Programmer's Reference
Guide (SPRU524).
Please see the nimu_eth.c file in the sample Ethernet driver code
packaged as NDK Support Package (NSP) for any C64x+ device for an
example NIMU API implementation.