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2 M
EMORY AND
A single-chip microcomputer using the S1C6200/6200A Core CPU has four major blocks: the
program memory (ROM), the data memory (RAM and I/O), the arithmetic logic unit (ALU) and the timing
generator circuit. This section describes each of these blocks in detail.
2.1 Program Memory (ROM)
Program memory contains the instructions that the CPU executes. Figure 2.1.1 shows the configuration of
the program memory.
Each instruction is a 12-bit word. Program memory can also be used for data tables for the table look-up
instructions.
There are two banks of program memory. Each bank is subdivided into 16 pages of 256 words (or steps).
That is:
Program memory = 2 banks
1 bank
1 page
1 step
Certain addresses in ROM have specific functions, as shown in Table 2.1.1.
Address
Bank 0, Page 1, Step 0
Bank 0, Page 1, Step 1 to 15
Bank 0, Page 0, Step 0 to 255
Bank 1, Page 1, Step 1 to 15
Bank 1, Page 0, Step 0 to 255
Bank 0
Page 1
Step 0
Reset vector
Step 1
Interrupt
vectors
Step 15
for Bank 0
Bank 0
Step 254
Step 0
Step 255
Bank 0
Page 0
Step 0
Step 1
12-bit
instructions
Step 254
Step 255
S1C6200/6200A CORE CPU MANUAL
O
PERATIONS
= 8,192 steps
= 4,096 steps
= 16 pages
= 256 steps
= 1 word
= 12 bits
Table 2.1.1 Allocated program memory
Reset vector
Interrupt vectors used while a program is running in bank 0
Bank 0, page 0 area
Direct call subroutines for use by CALZ while a program is running in bank 0
Interrupt vectors used while a program is running in bank 1
Bank 1, page 0 area
Direct call subroutines for use by CALZ while a program is running in bank 1
Bank 0
Bank 0
Bank 0
Page 14
Step 0
Step 1
Bank 0
Page 3
Page 2
Step 254
Step 255
PCP
(within bank)
(between banks)
PCB
Program or data
code area
Fig. 2.1.1 Program memory configuration
Function
Page 15
PCS
(within bank)
Bank 1
Step 0
Bank 1
Page 0
Step 0
Step 1
Step 254
Step 255
Program or data
code or CALZ
subloutines in
Bank 0
EPSON
2 MEMORY AND OPERATIONS
Bank 1
Bank 1
Bank 1
Page 14
Step 0
Step 1
Bank 1
Page 3
Page 2
Step 254
Step 255
Bank 1
Page 1
Step 0
Step 1
Interrupt
vectors
Step 15
for Bank 1
Step 254
Step 255
Program or data
code or CALZ
subloutines in
Bank 1
Page 15
3
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