![Tadpole SPARCbook 3 series Скачать руководство пользователя страница 21](http://html2.mh-extra.com/html/tadpole/sparcbook-3-series/sparcbook-3-series_reference-manual_3192948021.webp)
Architecture Overview
1-9
Slow I/O Subsystem
1.7
Slow I/O Subsystem
The Slow I/O subsystem is managed by an NCR89C105 SLAVIO. The
SLAVIO is an application specific integrated circuit (ASIC), designed as
part of a two-chip set with the NCR89C100 MACIO, which provides two
serial channels, keyboard and mouse ports, an interrupt controller and two
counter-timers. The key features of the SLAVIO include:
•
Two synchronous/asynchronous serial ports (85C30 SCC compatible)
•
Keyboard/mouse ports (85C30 SCC sub-set)
•
Two programmable counter-timers (500ns period)
•
Interrupt controller
•
8-bit expansion bus (EBus) interface/controller for EPROM and 8-bit
I/O devices
•
Internal 82077 style floppy disk controller
•
Miscellaneous I/O functions.
1.7.1
Serial Channels
The two serial ports are used to provide general purpose synchronous or
asynchronous RS232 interfaces. The SCC channels A and B are connected
to two 8-way mini-DIN connectors, which are marked as Serial Channel A
and Serial Channel B on the I/O panel at the rear of the SPARCbook 3
system unit.
The two remaining serial channels provide the keyboard and mouse
interfaces. These use transmit and receive data only. The TTL-level output
signals connect directly to the combined Keyboard/Mouse mini-DIN
connector on the I/O panel at the rear of the SPARCbook 3 unit.
For more information about these channels, refer to Chapter 4, “Serial
Interface”. For information about the connections of these channels, refer
to Appendix B, “Connector Information”.
1.7.2
Counter-Timers
The SLAVIO contains two counter timers. These are the System Counter
and the Processor Counter/User Timer which are clocked at 2MHz and can
provide counter-timer functions or periodic interrupts. The System Counter
is 22 bits wide, and increments every 500ns.
The Processor Counter/User Timer can be used in either the same mode as
the System Counter, or as a free running 54-bit timer. OpenBoot uses the
Processor Counter as a system watchdog timer.
S3GX_TRMBook Page 9 Friday, September 19, 1997 11:39 am
Содержание SPARCbook 3 series
Страница 1: ...Series Technical Reference Manual 980327 02 3 S3GX_TRMBook Page i Friday September 19 1997 11 39 am...
Страница 8: ...viii S3GX_TRMBook Page viii Friday September 19 1997 11 39 am...
Страница 28: ...1 16 Architecture Overview Microcontroller Subsystem S3GX_TRMBook Page 16 Friday September 19 1997 11 39 am...
Страница 44: ...2 16 The SPARC CPU SBus Controller S3GX_TRMBook Page 16 Friday September 19 1997 11 39 am...
Страница 76: ...5 8 SCSI Controller DMA Support S3GX_TRMBook Page 8 Friday September 19 1997 11 39 am...
Страница 82: ...6 6 Ethernet Interface DMA Support for Network Operations S3GX_TRMBook Page 6 Friday September 19 1997 11 39 am...
Страница 96: ...7 14 PCMCIA Interface Microcontroller Registers S3GX_TRMBook Page 14 Friday September 19 1997 11 39 am...
Страница 146: ...9 28 MODEM Class 2 Fax Command Set S3GX_TRMBook Page 28 Friday September 19 1997 11 39 am...
Страница 180: ...11 30 Display Interface RAMDAC S3GX_TRMBook Page 30 Friday September 19 1997 11 39 am...
Страница 210: ...B 10 Connector Information Removable Hard Drive SCSI Connector S3GX_TRMBook Page 10 Friday September 19 1997 11 39 am...
Страница 216: ...Index vi S3GX_TRMBook Page vi Friday September 19 1997 11 39 am...