Table of Contents
Advertisement
Programming
Am9513A Data Registers
The Am9513A Data Registers are used to read from or write to any of the 18 internal registers of
the Am9513A. The Am9513A Command Registers must be written to in order to select the
register to be accessed by the Am9513A Data Registers. The internal registers accessed by the
Am9513A Data Registers are as follows:
•
Counter Mode Registers for Counters 1, 2, 3, 4, and 5
•
Counter Load Registers for Counters 1, 2, 3, 4, and 5
•
Counter Hold Registers for Counters 1, 2, 3, 4, and 5
•
Compare Registers for Counters 1 and 2
•
Master Mode Register
All these registers are 16-bit registers that must be accessed through an 8-bit port, least
significant byte first. Bit descriptions for each of these registers are included in Appendix C,
AMD Am9513A Data Sheet.
Address:
Base address + 00 (hex) for Am9513A STC A
Base address + 02 (hex) for Am9513A STC B
Type:
Read-and-write
Word Size:
16-bit register, 8-bit port
Bit Map:
7
6
D15
D14
7
6
D7
D6
Bit
Name
7-0
D<15..8>
7-0
D<7..0>
PC-TIO-10 User Manual
5
4
D13
D12
5
4
D5
D4
Description
These eight bits are the most significant byte to be loaded into or
read from the Am9513A Internal Register currently selected.
These eight bits should be accessed after the eight bits of the least
significant byte are accessed.
These eight bits are the least significant byte to be loaded into or
read from the Am9513A Internal Register currently selected.
These eight bits should be accessed before the eight bits of the
most significant byte are accessed.
4-4
3
2
D11
D10
3
2
D3
D2
© National Instruments Corporation
Chapter 4
1
0
D9
D8
1
0
D1
D0
Advertisement
Table of Contents
