p8x32a Parallax, Inc., p8x32a Datasheet - Page 14

• Manufacturer Part Number: p8x32a
• Description: 8-cog Multiprocessor Microcontroller
• Manufacturer: Parallax, Inc.

Propeller™ P8X32A Datasheet
5.0
5.1.
The Main Memory is a block of 64 K bytes (16 K longs)
that is accessible by all cogs as a mutually-exclusive
resource through the Hub. It consists of 32 KB of RAM
and 32 KB of ROM. Main memory is byte, word and long
addressable.
5.1.1.
The 32 KB of Main RAM is general purpose and is the
destination of a Propeller Application either downloaded
from a host or from the external 32 KB EEPROM.
Copyright © Parallax Inc.
MEMORY ORGANIZATION
Main Memory
Main RAM
Figure 5: Propeller Font Character Set
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5.1.2.
The 32 KB of Main ROM contains all the code and data
resources vital to the Propeller chip’s function: character
definitions, log, anti-log and sine tables, and the Boot
Loader and Spin Interpreter.
5.1.3.
The first half of ROM is dedicated to a set of 256
character definitions. Each character definition is 16
pixels wide by 32 pixels tall. These character definitions
can be used for video generation, graphical LCD's,
printing, etc.
The character set is based on a North American / Western
European layout, with many specialized characters added
and inserted.
schematic building-block characters, Greek characters
commonly used in electronics, and several arrows and
bullets. (A corresponding Parallax True-Type Font is
installed with and used by the Propeller Tool software,
and is available to other Windows applications.)
The character definitions are numbered 0 to 255 from left-
to-right, then top-to-bottom, per Figure 5 below. They are
arranged as follows: Each pair of adjacent even-odd
characters is merged together to form 32 longs. The first
character pair is located in $8000-$807F. The second pair
occupies $8080-$80FF, and so on, until the last pair fills
$BF80-$BFFF.
Main ROM
Character Definitions
There are connecting waveform and
Rev 1.0 11/14/2007
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