The Terminal Address Register

base +2B16

The terminal address register is a read/write register that sets the last address of a memory segment. It is used with the base address registers to define the memory segment.

Address

7

6

5

4

3

2

1

0

 

 

 

 

 

 

 

 

 

base + 2B16

 

 

Terminal address

 

 

Base address

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Terminal Address. The terminal address field specifies the last address in a memory segment before returning to the base address.

Base Address. The Base Address (bit 0) is the most significant bit (bit 18) of the memory segment’s base address.

The Base Address Registers

base +2D16 and base +2F16

The base address registers are read/write registers that specify the beginning of a memory segment. This is the address where the segment starts after either being reset by the address count enable bit (bit 2) of the memory control register, or after reaching the terminal address.

Address

17

16

15

14

13

12

11

10

 

 

 

 

 

 

 

 

 

base + 2D16

 

 

Base address 0: start address MSByte

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Address

9

8

7

6

5

4

3

2

 

 

 

 

 

 

 

 

 

base + 2F16

 

 

Base address 1: start address LSByte

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The most significant byte of the segment’s base address is store in the least significant byte of register base +2D16 . The least significant byte of the base address is stored in the least significant byte of base +2F16. The data written to these registers is held in a temporary register until it is loaded into the actual address counter by clearing and then setting the address count enable bit (bit 2) of the memory control register (base +2116).

Appendix C

Register Programming 367

Page 367
Image 367
HP E1429A manual Terminal Address Register, Base Address Registers, Base +2B16, Base +2D16 and base +2F16