Ebus Leaf; Interrupts - Sun Microsystems Sun Blade 1000 Service Manual

In the Sun Blade 1000 and Sun Blade 2000 workstations, IEEE 1394 is used as the
interface for multimedia devices like digital cameras, digital video recorders, digital
video/versatile disks (DVD).
IEEE 1394 is a very flexible interconnect that supports multi-master, live
connect/disconnect, and dynamic node allocation. IEEE 1394 is based on a memory
type addressing (geographical addressing) with each node also acts as a repeater.
IEEE 1394 is an IEEE standard. The IEEE 1394 trade association web site is
http://www.1394ta.org/index.htm.
The PCIO-2 IEEE 1394 interface supports 100, 200, and 400 Mbps transfers. The IEEE
1394 block contains six DMA engines; four for isochronous transfers, and two for
asynchronous transfers. The engine implements the industry standard Descriptor
Based DMA Architecture (Open HCI). the PCIO-2 also implements the link layer and
it interfaces directly to a PHY chip.
The Sun Blade 1000 and Sun Blade 2000 workstations use a PHY with four ports.
Two of the ports are used by the workstation. There are two IEEE 1394 connectors on
the back panel.
C.1.4.3

EBus Leaf

EBus is a byte-wide I/O bus that provides the ability to interface to instruction set
architecture devices. In a Sun Blade 1000 and Sun Blade 2000 workstation there are
five devices on this bus: the boot PROM (Flash memory), the audio module, the
serial line controller, the SuperI/O chip, and the I2C controller.
The TOD clock function is implemented by the real time clock inside the SuperI/O
ASIC. The nonvolatile RAM is implemented by a I2C serial EEPROM and part of the
boot PROM.
The EBus channel engine also supports four DMA controllers with programmable
transfer size and chained and unchained mode. Only two devices support slave
DMA transfers on EBus: SuperI/O for the floppy disk interface (single DMA engine)
and the parallel port (single DMA engine), and the audio CODEC for audio
playback and capture (two DMA engines).
C.1.5

Interrupts

The interrupt model used in the Sun Blade 1000 and Sun Blade 2000 workstation
uses the Sun4u/Sun5 architecture. Interrupts are delivered to the processor(s) as
Mondo vectors. The CPU receives interrupt packets that are issued over the Sun
CrossBar Interconnect bus. The processors can issue interrupts to each other (called
cross-calls). They are issued by SBC for I/O interrupts. All interrupts that are not
cross-called are referred to as I/O interrupts.
C-22 Sun Blade 1000 and Sun Blade 2000 Service Manual • January 2002