Sun Microsystems 60 service manual ASICs, Scsi ID Selection, 15.1 K9+

C.1.14.5 SCSI ID Selection

The motherboard host adapter is assigned the SCSI identification of 7 for both ports. The two internal drives attached to the SCA-2 connectors have a SCSI identification of 0 and 1, while the CD-ROM has an identification of 6.

C.1.15 ASICs

The system unit achieves a high level of integration through application-specific intergrated circuits (ASICs). All ASICs are 1149.1 (JTAG) compliant. The following ASICs are highlighted and are described in the following subsections:

■K9+

■Marvin

■PCI-to-EBus/Ethernet controller (Cheerio)

■UPA-to-PCI bridge (PSYCHO+)

■Frame buffer controller (FBC)

■Reset, interrupt, scan, and clock (RISC)

Also included in this section are brief discussions of the SuperIO component.

C.1.15.1 K9+

The K9+ ASIC is a buffered memory crossbar device that acts as the bridge between the six system unit buses. The six system unit buses include two processor buses (144 bits wide), a memory data bus (two busses, each 288 bits wide), a graphics bus, and two I/O buses. The chip is bit-sliced such that 9 parts are required to implement a full connection to the system.

The K9+ ASIC provides the following:

Note –Referred data formats are as follows: a byte is 8 bits, a halfword is 16 bits, a word is 32 bits, and a doubleword is 64 bits.

■Six-port crossbar

■Decoupled memory port; loading and unloading of memory data can take place in parallel with other operations

■Burst transfers operate on a doubleword of data per slice

■A total of eight two-entry first-in-first-out (FIFO) devices for read data storage

■Power-up safe buses (tristated)

Appendix C Functional Description C-33