HD6433694 Datasheet, PDF (92/432 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Tiny Series

BDRH for byte access. For word access, the data bus used depends on the address. See section
4.1.1, Address Break Control Register (ABRKCR), for details. The initial value of this register is
undefined.
4.2 Operation
When the ABIF and ABIE bits in ABRKSR are set to 1, the address break function generates an
interrupt request to the CPU. The ABIF bit in ABRKSR is set to 1 by the combination of the
address set in BAR, the data set in BDR, and the conditions set in ABRKCR. When the interrupt
request is accepted, interrupt exception handling starts after the instruction being executed ends.
The address break interrupt is not masked by the I bit in CCR of the CPU.
Figures 4.2 show the operation examples of the address break interrupt setting.
When the address break is specified in instruction execution cycle
Register setting
• ABRKCR = H'80
• BAR = H'025A
Program
0258 NOP
* 025A NOP
025C MOV.W @H'025A,R0
0260 NOP
0262 NOP
:
:
Underline indicates the address
to be stacked.
φ
Address
bus
Interrupt
request
NOP NOP MOV MOV
instruc- instruc- instruc- instruc-
tion
tion tion 1 tion 2 Internal
prefetch prefetch prefetch prefetch processing
Stack save
0258 025A 025C 025E
Interrupt acceptance
SP-2 SP-4
Figure 4.2 Address Break Interrupt Operation Example (1)
Rev. 4.00, 03/04, page 64 of 400