SH7641 Datasheet, PDF (316/1036 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH™ RISC engine Family / SH7641 Series

Section 11 User Break Controller (UBC)
Break Condition Specified for I Bus Data Access Cycle:
(Example 3-1)
• Register specifications
BARA = H'00314156, BAMRA = H'00000000, BBRA = H'0094, BARB = H'00055555,
BAMRB = H'00000000, BBRB = H'00A9, BDRB = H'00007878, BDMRB = H'00000F0F,
BRCR = H'00000080
Specified conditions: Channel A/channel B independent mode
<Channel A>
Address: H'00314156, Address mask: H'00000000
Bus cycle: I bus/instruction fetch/read (operand size is not included in the condition)
<Channel B>
Address: H'00055555, Address mask: H'00000000
Data:
H'00000078, Data mask: H'0000000F
Bus cycle: I bus/data access/write/byte
On channel A, a user break occurs when instruction fetch is performed for address H'00314156
in the memory space.
On channel B, a user break occurs when the I bus writes byte data H'7* in address
H'00055555.
11.4 Usage Notes
1. The CPU can read from or write to the UBC registers via the I bus. Accordingly, during the
period from executing an instruction to rewrite the UBC register till the new value is actually
rewritten, the desired break may not occur. In order to know the timing when the UBC register
is changed, read from the last written register. Instructions after then are valid for the newly
written register value.
2. UBC cannot monitor access to the L bus and I bus in the same channel.
3. Note on specification of sequential break:
A condition match occurs when a B-channel match occurs in a bus cycle after an A-channel
match occurs in another bus cycle in sequential break setting. Therefore, no break occurs even
if a bus cycle, in which an A-channel match and a channel B match occur simultaneously, is
set.
Rev. 4.00 Sep. 14, 2005 Page 266 of 982
REJ09B0023-0400