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1 register descriptions, 1 trapa exception register (tra) – Renesas SH7641 User Manual

Page 248

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Section 9 Exception Handling

Rev. 4.00 Sep. 14, 2005 Page 198 of 982

REJ09B0023-0400

9.1 Register

Descriptions

There are three registers for exception handling. A register with an undefined initial value should
be initialized by the software.

• TRAPA exception register (TRA)
• Exception event register (EXPEVT)
• Interrupt event register 2 (INTEVT2)

Figure 9.1 shows the bit configuration of each register.

31

TRA

EXPEVT

INTEVT2

TRA

EXPEVT

INTEVT2

10 9

2 1 0

31

12 11

0

0

0

0

0

31

12 11

0

Figure 9.1 Register Bit Configuration

9.1.1

TRAPA Exception Register (TRA)

TRA is assigned to address H'FFFFFFD0 and consists of the 8-bit immediate data (imm) of the
TRAPA instruction. TRA is automatically specified by the hardware when the TRAPA instruction
is executed. Only bits 9 to 2 of the TRA can be re-written using the software.

Bit Bit

Name

Initial
Value R/W Description

31 to 10

 R Reserved

These bits are always read as 0. The write value
should always be 0.

9 to 2

TRA

R/W

8-Bit Immediate Data

1, 0

 R Reserved

These bits are always read as 0. The write value
should always be 0.

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