
Chapter 2
2.4 Memory Organization
The EM60000 series provide 8K words of program memory and 144 bytes of
data memory. The system control registers and all I/O ports are mapped to data
memory locations.
2.4.1 Data Memory
All the 144 bytes data memory of EM60000 series can be made the operand of
an instruction. The data memory address range is from 0x00 to 0x3F. The
lower address locations (0x00 to 0x1F) are reserved for the system control
registers, I/O port data registers, and some other general-purpose data memory.
The higher locations (0x20 to 0x3F) are the general-purpose data memory and
are divided into 4 memory banks. When using the "banked" area of the data
memory, you must set the memory bank select bit (in the RAM Select Register,
R4) before accessing the desired data memory. The following table shows the
contents of "unbanked" and "banked" areas of the data memory.
1. Unbanked Area: Address Table of System Control Registers and
Data Memory.
Address
Symbol
Description
0x00
R0
Indirect address register
0x01
R1 (TCC)
8-bit general purpose timer register
0x02
R2 (PC)
Lower 8-bit of program counter
0x03
R3 (SF)
Status flag register
0x04 R4
(RSR)
RAM select register for selecting memory bank and indirect
address register
0x05
R5 (INTC)
Interrupt control register for interrupt enable function and flag
0x06
R6 (MTC)
8-bit general purpose timer register for melody playing
0x07
R7
Not used or invalid address
0x08
R8
I/O ports pull-low, wake-up and watchdog timer control register
0x09
R9
Bank select register for special function control registers
0x0A
R10 (MODE)
Special control register for speech, melody & DAC
0x0B
RB
Port 1 input data register
0x0C
RC
Port 2 I/O data register
0x0D
RD
Port 3 I/O data register
0x0E
RE
Port 4 I/O data register
0x0F
RF
Port 5 output data register
0x10
R10 (MULT)
Multiplicand data for the multiplier
0x11
R11 (PRODL)
Low byte of product result from the multiplier
0x12
R12 (PRODH) High byte of product result from the multiplier
0x13
…
0x1F
R13 to R1F
General-purpose data memory for user
EM60000 Series User’s Manual
Architecture
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