SH7720 Datasheet, PDF (1192/1524 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7700 Series

Section 33 User Break Controller (UBC)
3. When the data value is included in the break conditions on channel B:
When the data value is included in the break conditions, either longword, word, or byte is
specified as the operand size of the break bus cycle register B (BBRB). When data values are
included in break conditions, a break is generated when the address conditions and data
conditions both match. To specify byte data for this case, set the same data in two bytes at bits
15 to 8 and bits 7 to 0 of the break data register B (BDRB) and break data mask register B
(BDMRB). When word or byte is set, bits 31 to 16 of BDRB and BDMRB are ignored. Set the
word data in bits 31 to 16 in BDRB and BDMRB when including the value of the data bus as a
break condition for the MOVS.W @-As,Ds, MOVS.W @As,Ds, MOVS.W @As+,Ds, or
MOVS.W @As+Ix,Ds instruction (bits 15 to 0 are ignored).
4. Access by a PREF instruction is handled as read access in longword units without access data.
Therefore, if including the value of the data bus when a PREF instruction is specified as a
break condition, a break will not occur.
5. If the L bus is selected, a break occurs on ending execution of the instruction that matches the
break condition, and immediately before the next instruction is executed. However, when data
is also specified as the break condition, the break may occur on ending execution of the
instruction following the instruction that matches the break condition. If the I bus is selected,
the instruction at which the break will occur cannot be determined. When this kind of break
occurs at a delayed branch instruction or its delay slot, the break may not actually take place
until the first instruction at the branch destination.
33.3.4 Break on X/Y-Memory Bus Cycle
1. The break condition on an X/Y-memory bus cycle is specified only in channel B. If the XYE
bit in BBRB is set to 1, the break address and break data on X/Y-memory bus are selected. At
this time, select the X-memory bus or Y-memory bus by specifying the XYS bit in BBRB. The
break condition cannot include both X-memory and Y-memory at the same time. The break
condition is applied to an X/Y-memory bus cycle by specifying L bus/data access/read or
write/word or no specified operand size in the break bus cycle register B (BBRB).
2. When an X-memory address is selected as the break condition, specify an X-memory address
in the upper 16 bits in BARB and BAMRB. When a Y-memory address is selected, specify a
Y-memory address in the lower 16 bits. Specification of X/Y-memory data is the same for
BDRB and BDMRB.
3. The timing of a data access break for the X memory or Y memory bus to occur is the same as a
data access break of the L bus. For details, see No.5 in section 33.3.3, Break on Data Access
Cycle.
Rev. 3.00 Jan. 18, 2008 Page 1130 of 1458
REJ09B0033-0300