Table of Contents
Advertisement
Programming
Am9513A Status Registers
The Am9513A Status Registers give information about the output pin status of each counter in
the Am9513A. In addition, these registers indicate the current setting of the byte pointer, which
indicates whether the next byte to be accessed is the most significant byte or the least significant
byte.
Address:
Base address + 01 (hex) for Am9513A STC A
Base address + 03 (hex) for Am9513A STC B
Type:
Read-only
Word Size:
8-bit register, 8-bit port
Bit Map:
7
6
X
X
OUT5
Bit
Name
7-6
X
5-1
OUT<5..1>
0
BYTE POINTER
PC-TIO-10 User Manual
5
4
OUT4
OUT3
Description
Unused bits. They may be returned as 0 or 1.
Each of these five bits returns the logic state of the associated
counter output pin. For example, if the bit OUT4 is set, then the
output pin of Counter 4 (or Counter 9) is at a logic-high state.
This bit represents the state of the Am9513A Byte Pointer Flip-
Flop. If this bit is set, the next byte to be written to or read from
the Data Port is the least significant byte; if this bit is clear, the
next byte to be written to or read from the Data Port is the most
significant byte.
3
2
OUT2
OUT1
4-6
1
0
BYTE POINTER
© National Instruments Corporation
Chapter 4
Advertisement
Table of Contents
