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This version: MSeSpM. 169392838
Previous version: Mar. 1996
4-Bit Microcontroller with Built-in POCSAG Decoder and Melody Circuit, Operating at
0.9 V (Min.)
The MSM63238 is a CMOS 4-bit microcontroller with a built-in POCSAG (Post Office Code
Standardization Advisory Group) decoder.
The MSM63238 employs Oki's original nX-4/250 CPU core and is suitable for pager applications.
The MSM63P238 is a one-time-programmable ROM-version product having one-time PROM
(OTP) as internal program memory.
The specifications of the MSM63P238 are equal to those of the MSM63238 except for electrical
characteristics, packaging (only 80-pin flat package is available for the MSM63P238), and some
• Rich instruction set
Transfer, rotate, increment/decrement, arithmetic operations, comparison, logic operations,
mask operations, bit operations, ROM table reference, external memory transfer, stack
operations, flag operations, branch, conditional branch, call/return, control.
• Rich selection of addressing modes
Indirect addressing of four data memory types, with current bank register, extra bank
register, HL register and XY register.
Data memory bank internal direct addressing mode.
• Processing speed
Two clocks per machine cycle, with most instructions executed in one machine cycle.
Minimum instruction execution time : 61 ms (@ 32.768 kHz system clock)
1 ms (@ 2 MHz system clock)
• Clock generation circuit
: 32.768 kHz/38.4 kHz/76.8 kHz crystal oscillator
: 2 MHz (Max.) RC or ceramic oscillator select
• Program memory space
Basic instruction length is 16 bits/1 word
• Data memory space
• External data memory space
64 Kbytes (expandable by using an I/O port)