User`s guide

26 • Operation Theory
4
Operation Theory
This chapter provides the detailed operation information for the
cPCI/PCI-7300A, including I/O configuration, block diagram, input/output FIFO,
bus -mastering DMA, scatter/gather, clocking mode, starting mode, termination,
I/O transfer mode, and auxiliary digital I/O.
4.1 I/O Configuration
The 32-bit I/O data path of PCI-7300A can be configured as 8-bit, 16-bit, or
32-bit, the possible configuration modes are listed as follows.
Mode Channel Description
DI32 PORTA (DI0…DI15)
PORTB (DI16..DI31)
Both PORTA and PORTB
are configured as input
channel
DO32 PORTA
(DO16…DO31)
PORTB
(DO0…DO15)
Both PORTA and PORTB
are configured as output
channel
DI16DO16
(default mode)
PORTA (DI0…DI15)
PORTB
(DO0…DO15)
PORTA is 16-CH input
PORTB is 16-CH output
DI16DO8 PORTA (DI0…DI15)
PORTB (DO0…DO7)
PORTA is 16-CH input
PORTB is 8-CH output
DI8DO16 PORTA (DI0…DI7)
PORTB
(DO0…DO15)
PORTA is 8-CH input
PORTB is 16-CH output
DI8DO8 PORTA (DI0…DI7)
PORTB (DO0…DO7)
PORTA is 8-CH input
PORTB is 8-CH output