Vax 613 0S Instruction Manual Page 144

  • Download
  • Add to my manuals
  • Print
  • Page
    / 344
  • Table of contents
  • BOOKMARKS
  • Rated. / 5. Based on customer reviews
Page view 143
8.3 NCR 53C94 Registers (300/400/500 Models)
The 53C94 registers are accessed as bits<7:0> of the addressed longword. Each
register is addressed by adding the offset listed in the next table to the base
address listed in the next table. Write operations to the remaining bits are
ignored, and read operations are UNPREDICTABLE. The TURBOchannel byte
mask is ignored write operations to these registers.
Use of these registers is described in Section 9.6.3. For further information, refer
to the NCR 53C94-95-96 Advanced SCSI Controller specification.
GPI bit <2> (readable in CIR<6>) reports the SCSI chip oscillator frequency. A
value of 1 indicates that the oscillator is 25 MHz, enabling slow data transfers.
The registers’ location, format, and contents are:
Base Address Register
400/500 Models
1.C008.0000 SCSI[0] 53C94 registers
1.C008.0100 SCSI[1] 53C94 registers
300 Models
1.8008.0000 SCSI[0] 53C94 registers
1.8008.0100 SCSI[1] 53C94 registers
Offset Register Read Register Write
00 Transfer counter LSB Transfer count
LSB
04 Transfer counter MSB Transfer count
MSB
08 FIFO FIFO
0C Command Command
10 Status Destination
bus ID
14 Interrupt Select/reselect
_& timeout
18 Sequence Step Synchronous
period
1C FIFO Flags Synchronous
offset
20 Configuration 1 Configuration 1
24 Reserved Clock
conversion
factor
28 Reserved Test mode
2C Configuration 2 Configuration 2
30 Configuration 3 Configuration 3
8–12 TURBOchannel Dual SCSI ASIC
Page view 143
1 2 ... 139 140 141 142 143 144 145 146 147 148 149 ... 343 344

Comments to this Manuals

No comments