Hitachi H8S/2633 Hardware Manual page 54

Exception Vector Table and Memory Indirect Branch Addresses: In advanced mode the top

area starting at H'00000000 is allocated to the exception vector table in units of 32 bits. In each 32

bits, the upper 8 bits are ignored and a branch address is stored in the lower 24 bits (figure 2-4).

For details of the exception vector table, see section 4, Exception Handling.

The memory indirect addressing mode (@@aa:8) employed in the JMP and JSR instructions uses

an 8-bit absolute address included in the instruction code to specify a memory operand that

contains a branch address. In advanced mode the operand is a 32-bit longword operand, providing

a 32-bit branch address. The upper 8 bits of these 32 bits are a reserved area that is regarded as

H'00. Branch addresses can be stored in the area from H'00000000 to H'000000FF. Note that the

first part of this range is also the exception vector table.

Power-on reset exception vector

Manual reset exception vector

(Reserved for system use)

Exception vector 1

Figure 2-4 Exception Vector Table (Advanced Mode)

Exception vector table