Register Descriptions; Figure 5.1 Register Bit Configurations - Hitachi SH7751 Hardware Manual

5.2

Register Descriptions

There are three registers related to exception handling. Addresses are allocated for these, and can
be accessed by specifying the P4 address or area 7 address.
1. The exception event register (EXPEVT) resides at P4 address H'FF00 0024, and contains a 12-
bit exception code. The exception code set in EXPEVT is that for a reset or general exception
event. The exception code is set automatically by hardware when an exception is accepted.
EXPEVT can also be modified by software.
2. The interrupt event register (INTEVT) resides at P4 address H'FF00 0028, and contains a 14-
bit exception code. The exception code set in INTEVT is that for an interrupt request. The
exception code is set automatically by hardware when an exception is accepted. INTEVT can
also be modified by software.
3. The TRAPA exception register (TRA) resides at P4 address H'FF00 0020, and contains 8-bit
immediate data (imm) for the TRAPA instruction. TRA is set automatically by hardware when
a TRAPA instruction is executed. TRA can also be modified by software.
The bit configurations of EXPEVT, INTEVT, and TRA are shown in figure 5.1.
EXPEVT
31
0
INTEVT
31
0
TRA
31
0
0: Reserved bits. These bits are always read as 0, and should only be written
with 0.
imm: 8-bit immediate data of the TRAPA instruction
Rev. 3.0, 04/02, page 120 of 1064

Figure 5.1 Register Bit Configurations

12 11
0 Exception code
14 13
0 Exception code
10 9
0 imm
0
0
2 1 0
0 0