Effective Address Calculation - Hitachi H8S/2646 Hardware Manual

Hitachi 16-bit single-chip microcomputer h8s/2646 series

Table of Contents

(a) Normal Mode *

Note: * Not available in the H8S/2646 Series.

Figure 2-13 Branch Address Specification in Memory Indirect Mode

If an odd address is specified in word or longword memory access, or as a branch address, the

least significant bit is regarded as 0, causing data to be accessed or instruction code to be fetched

at the address preceding the specified address. (For further information, see section 2.5.2, Memory

Data Formats.)

Effective Address Calculation

Table 2-6 indicates how effective addresses are calculated in each addressing mode. In normal

mode* the upper 8 bits of the effective address are ignored in order to generate a 16-bit address.

Note: * Not available in the H8S/2646 Series.

Branch address

Branch address

(b) Advanced Mode