REV.-A
2 . 4 . 3 D a t a F l o w
This section describes the firmware start-up operation when the printer is initialized, data flow
(especially printing data flow), and command processing.
LX-800.
AOOOI
80001
00001
CPU Internal
Area
(Down Load Area)
Not Used
Gate
Function
Address Area
(Memory Mapped
Not Used
Buffer and Work Area
(RAM
8k
Program Area
(ROM
Figure 2-13 shows a memory map of the
Stack Area
Buffer
(2K bytes)
Buffer
I
I
Fig. 2-13. LX-800 Memory M a p
The CPU can access an external memory of 64K bytes, and executes the program
bytes) in the
external ROM
The external RAM
area (8K bytes) and the CPU internal RAM (256 bytes)
are used as a buffer and working area. The CPU accesses the gate array using the instruction codes
(See Table 2-4).
through
are defined as memory mapped 1/0.
2-18
