Chapter 2
General Description
© National Instruments Corporation
2-5
GPIB-1014 User Manual
Table 2-3. 68450 Internal DMA Registers (continued)
Address (Base
+ Hex Offset)
Mode
Register
Channel
Size
85
R/W
Operation Control
(OCR2)
2
8 bits
86
R/W
Sequence Control
(SCR2)
2
8 bits
87
R/W
Channel Control
(CCR2)
2
8 bits
AD
R/W
Channel Priority
(CPR2)
2
8 bits
A5
R/W
Normal Interrupt Vector
(NIVR2)
2
8 bits
A7
R/W
Error Interrupt Vector
(EIVR2)
2
8 bits
CA
R/W
Memory Transfer Counter
(MTCR3)
3
16 bits
CC
R/W
Memory Address Register
(MAR3)
3
32 bits
E9
R/W
Memory Function Code
(MFCR3)
3
8 bits
D4
R/W
Device Address Register
(DAR3)
3
32 bits
F1
R/W
Device Function Code
(DFCR3)
3
8 bits
DA
R/W
Base Transfer Counter
(BTCR3)
3
16 bits
DC
R/W
Base Address Register
(BAR3)
3
32 bits
F9
R/W
Base Function Code
(BFCR3)
3
8 bits
C0
R/W
Channel Status
(CSR3)
3
8 bits
C1
R
Channel Error
(CER3)
3
8 bits
C4
R/W
Device Control
(DCR3)
3
8 bits
C5
R/W
Operation Control
(OCR3)
3
8 bits
C6
R/W
Sequence Control
(SCR3)
3
8 bits
C7
R/W
Channel Control
(CCR3)
3
8 bits
ED
R/W
Channel Priority
(CPR3)
3
8 bits
E5
R/W
Normal Interrupt Vector
(NIVR3)
3
8 bits
E7
R/W
Error Interrupt Vector
(EIVR3)
3
8 bits
FF
R/W
General Control Register
(GCR)
all
8 bits
Table 2-4. GPIB-1014 Configuration Registers
Address
(Base + Hex Offset)
Mode
Register
Size
101
W
Configuration Register 1
8 bits
105
W
Configuration Register 2
8 bits
VMEbus Master-Direct Memory Access
The GPIB-1014 can function as a VMEbus master, performing data transfers to and from
VMEbus memory. In most applications, the 68450 controls the data transfer to and from the
GPIB during DMA, and can transfer the 8-bit data on data lines D07 through D00 or D15
through D08, allowing the packing of data in VMEbus memory. In addition to GPIB-to-VMEbus
memory DMA transfers, the board can also perform 8- or 16-bit memory-to-memory DMA
transfers.