National Instruments AT-MIO-16X Programming the RTSI Switch

Chapter 5 Programming

National Instruments Corporation 5-39 AT-MIO-16X User Manual

Note: If both the A2DRV and A2RCV bits are set, the GATE1 signal is driven by

the signal OUT2. This arrangement is probably not desirable.

• To drive the RTSI switch pin A4 with the signal OUT5, set

the A4DRV bit in Command Register 2. Otherwise, clear the

A4DRV bit.

• To drive the signal TMRT RIG* from pin A4 of the RT SI sw itch,

set the A4RCV bit in Command Register 2. Otherwise, clear the

A4RCV bit.

Note: If both the A4DRV and A4RCV bits are set, the TMRTRIG* signal is driven

by the signal OUT5.

Programming the RTSI Switch

The RTSI switch is a 7×7 crossbar switch which can be programmed to

connect any of the signals on the A side to any of the signals on the

B side and vice versa. To do this, a 56-bit pattern is shifted into the

RTSI switch by writing one bit at a time to the RTSI Switch Shift

pattern into the RTSI switch.

The 56-bit pattern is made up of two 28-bit patterns, one for side A and

one for side B of the RTSI switch. The low-order 28 bits select the

signal sources for the B-side pins. The high-order 28 bits select the

signal sources for the A-side pins. Each of the 28-bit patterns are made

up of seven 4-bit fields, one for each pin. The 4-bit field select s the

signal source and the output enable for the pin. Figure 5-10 shows the

bit map of the RTSI switch 56-bit pattern.