122-32000 Parallax Inc, 122-32000 Datasheet - Page 31

• Manufacturer Part Number: 122-32000
• Description: MANUAL PROPELLER
• Manufacturer: Parallax Inc

Specifications of 122-32000

• Accessory Type: Manual
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: Propeller Education (PE) Kit
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

ROM. The 32 KB of Main RAM is general purpose and is the destination of a Propeller
Application either downloaded from a host or uploaded from the external 32 KB EEPROM.
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. The Main Memory organization is shown in Figure 1-5.
Main RAM
The first half of Main Memory is all RAM. This space is used for your program, data,
variables and stack(s); otherwise known as your Propeller Application.
When a program is loaded into the chip, either from a host or from an external EEPROM, this
entire memory space is written. The first 16 locations, $0000 – $000F, hold initialization data
used by the Boot Loader and Interpreter. Your program’s executable code and data will
begin at $0010 and extend for some number of longs. The area after your executable code,
extending to $7FFF, is used as variable and stack space.
There are two values stored in the initialization area that might be of interest to your program:
a long at $0000 contains the initial master clock frequency, in Hertz, and a byte following it
at $0004 contains the initial value written into the CLK register. These two values can be
read/written using their physical addresses (
their predefined names (
the
reference them will have current information.
CLOCKSET
command, you will also need to update these two locations so that objects which
CLKFREQ
and
CLKMODE
LONG[$0]
). If you change the CLK register without using
and
BYTE[$4]
Propeller Manual v1.0 · Page 31
) and can be read by using
Figure 1-5: Main
Memory Map