MITSUBISHI MICROCOMPUTERS
7477/7478 GROUP
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
PROGRAMMING NOTES
(1) The frequency ratio of the timer is 1/(n+1).
(2) The contents of the interrupt request bits are not modified im-
mediately after they have been written. After writing to an
interrupt request register, execute at least one instruction be-
fore executing a BBC or BBS instruction.
(3) To calculate in decimal notation, set the decimal mode flag (D)
to “1”, then execute an ADC or SBC instruction. Only the ADC
and SBC instruction yield proper decimal results. After execut-
ing an ADC or SBC instruction, execute at least one
instruction before executing a SEC, CLC, or CLD instruction.
(4) An NOP instruction must be used after the execution of a PLP
instruction.
(5) Do not execute the STP instruction during A-D conversion.
(6) In the 7477 group, set bit 0, bit 1, and bit 3 – bit 7 to “0” of the
CPU mode register.
(7) Multiply/Divide instructions
The index X mode (T) and the decimal mode (D) flag do not
affect the MUL and DIV instruction.
The execution of these instructions does not modify the con-
tents of the processor status register.
DATA REQUIRED FOR MASK ORDERING
Please send the following data for mask orders.
(1) mask ROM confirmation form
(2) mark specification form
(3) ROM data ......................................................... EPROM 3 sets
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MITSUBISHI [ Mitsubishi Group ]
