Chapter 2 Register Map and Descriptions
Static DIO Register-Level Programmer Manual
2-2
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Table 2-1.
NI 6509/651
x
/6520/6521/6528 Register Address Map—Recurring Port Registers
Register Name
Short Name
Offset (Hex)
Type
Size
IO Port Data
IOPort(
N
)Data
0x40 + 0x
N
0
Read-write
8-bit
IO Select
IOSelect(
N
)
0x41 + 0x
N
0
Read-write
8-bit
Rising Edge Sensitivity
Configuration
RiseEdgeEnable(
N
)
0x42 + 0x
N
0
Read-write
8-bit
Falling Edge Sensitivity
Configuration
FallEdgeEnable(
N
)
0x43 + 0x
N
0
Read-write
8-bit
Filter Enable
FilterEnable(
N
)
0x44 + 0x
N
0
Read-write
8-bit
Watchdog Timer High
Impedance
WatchdogHighImp(
N
)
0x46 + 0x
N
0
Read-write
8-bit
Watchdog Timer Enable
WatchdogEnable(
N
)
0x47 + 0x
N
0
Read-write
8-bit
Watchdog Timer High
or Low
WatchdogHighLow(
N
)
0x48 + 0x
N
0
Read-write
8-bit
RTSI Enable
RTSI_En(
N
)
0x49 + 0x
N
0
Read-write
8-bit
Note
:
N
is the port number in hexidecimal. Ports can range from 0 to 11 (0x0 to 0xB), depending on your device. For each
port, you must add an additional offset equal to 0x10 times the port number in hex.
Examples:
1. Offset of Port 6 Data Register (IOPort6Data) = 0x40 + 0x60 = 0xA0
2. Offset of Port 11 Filter Enable Register (FilterEn11) = 0x44 + 0xB0 = 0xF4
Table 2-2.
NI 6509/651
x
/6520/6521/6528 Register Address Map—Non-recurring Registers
Register Name
Offset
(Hex)
Type
Size
ID Register
0x00
Read
8-bit
Clear Register
0x01
Write strobe
8-bit
Change Status Register
0x02
Read
8-bit
Master Interrupt Control Register
0x03
Read-write
8-bit
Revision Register
0x04
Read
32-bit
Filter Interval 32-bit Register
0x08
Read-write
32-bit
Automatic Clock Selection Register
0x14
Bit 0:
Write
Bit 1:
Read
8-bit