R01UH0823EJ0100 Rev.1.00
Page 316 of 1823
Jul 31, 2019
RX23W Group
16. Buses
16.4.2
Operations When a Bus Error Occurs
When a bus error occurs, the error is indicated to the CPU. Operation is not guaranteed when a bus error occurs.
Bus error indication to the CPU
An interrupt is generated. The IERn register in the ICU can specify whether to generate an interrupt in the case of a
bus error.
16.4.3
Conditions Leading to Bus Errors
lists the types of bus errors for each area in the respective address space.
If an illegal address access error or timeout is detected when no bus error has occurred (bus error status register n
(BERSRn; n = 1 or 2) is cleared), the detected error is reflected on the BERSRn. Once a bus error occurs, no subsequent
bus errors are reflected on the register unless the register is cleared.
If bus errors are simultaneously caused by two or more bus masters, error information of only one bus master is reflected.
Once a bus error occurs, the status is retained until BERSRn is cleared.
—:
A bus error does not result.
:
A bus error may or may not result.
:
A bus error results.
Note:
The capacity of the RAM, E2 DataFlash, and ROM differs depending on the product. For details, see section 49, RAM, section
50, Flash Memory (FLASH).
Table 16.5
Types of Bus Errors
Address
Type of Area
Type of Error
Illegal Address Access
Timeout
0000 0000h to 0007 FFFFh
Memory bus 1
—
—
0008 0000h to 0008 7FFFh
Internal peripheral bus 1
—
—
0008 8000h to 0009 FFFFh
Internal peripheral bus 2
—
000A 0000h to 000B FFFFh
Internal peripheral bus 3
—
000C 0000h to 000D FFFFh
Internal peripheral bus 4
000E 0000h to 000F FFFFh
Reserved area
—
—
0010 0000h to 0011 FFFFh
Internal peripheral bus 6
—
—
0012 0000h to 007F FFFFh
—
0080 0000h to 00FF FFFFh
—
—
0100 0000h to 07FF FFFFh
Reserved area
—
—
0800 0000h to 0FFF FFFFh
—
—
1000 0000h to 7FFF FFFFh
—
8000 0000h to FEFF FFFFh
Memory bus 2
—
—
FF00 0000h to FF7F FFFFh
—
—
FF80 0000h to FFFF FFFFh
—
—