Memory Organization
Chapter 7
7-6
Data Table Areas
The following areas make up the data table. They are:
processor work area no. 1
output image table
bit/word storage (020-027)
timer/counter accumulated values and internal storage
processor work area no. 2
input image table
bit/word storage (120-127)
timer/counter preset values and internal storage
Chapter 2 describes the input and output image tables. The following
sections describe the remaining areas.
Processor Work Areas
There are two processor work areas. They are located at addresses 000 00
to 007 17 and 100 00 to 107 17. The processor uses these 16 words for its
internal control functions. You cannot address these data table words.
Bit/Word Storage
There are two bit/word storage areas (providing you are not using 1-slot
addressing). They are located at addresses 020-026 and 120-127.
Diagnostic Word: Word 027
Bits in word 027 are used by the processor for internal control functions.
This Bit:
Stores this Information:
00
(Battery low) - set when the battery is low.
01
(EEPROM) - set indicates that EEPROM transferred at powerup.
This bit is always reset (0) when the processor powers down
02
(STI too long) - set indicates subroutine execution time plus program
transition time exceed service time.
03
Reserved.
04
05
06
07
Reserved for Data Highway - set when the processor is connected to
the line and actively communicating with the Data Highway.
1015
Used in Report Generation for message request bits
16
Report Generation Busy bit
17
Report Generation Done bit
