HD6433640 HITACHI [Hitachi Semiconductor], HD6433640 Datasheet - Page 29

• Manufacturer Part Number: HD6433640
• Description: H8/3644 Series Hardware Manual
• Manufacturer: HITACHI [Hitachi Semiconductor]

2.2.3
In reset exception handling, the program counter (PC) is initialized by a vector address (H'0000)
load, and the I bit in the CCR is set to 1. The other CCR bits and the general registers are not
initialized. In particular, the stack pointer (R7) is not initialized. The stack pointer should be
initialized by software, by the first instruction executed after a reset.
2.3
The H8/300L CPU can process 1-bit data, 4-bit (BCD) data, 8-bit (byte) data, and 16-bit (word)
data.
The H8/300L CPU can process 1-bit, 4-bit BCD, 8-bit (byte), and 16-bit (word) data. 1-bit data is
handled by bit manipulation instructions, and is accessed by being specified as bit n (n = 0, 1, 2, ...
7) in the operand data (byte).
Byte data is handled by all arithmetic and logic instructions except ADDS and SUBS. Word data
is handled by the MOV.W, ADD.W, SUB.W, CMP.W, ADDS, SUBS, MULXU ( b bits 8 bits),
and DIVXU (16 bits 8 bits) instructions.
With the DAA and DAS decimal adjustment instructions, byte data is handled as two 4-bit BCD
data units.
Initial Register Values
Data Formats
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