HD6475328-CP10 HITACHI [Hitachi Semiconductor], HD6475328-CP10 Datasheet - Page 94

• Manufacturer Part Number: HD6475328-CP10
• Description: original Hitachi CMOS microcomputer unit (MCU)
• Manufacturer: HITACHI [Hitachi Semiconductor]

(1) The BREQ pin is sampled at the start of a T
(2) At the end of the internal operation cycle, the BACK pin goes Low and the CPU releases the bus.
(3) The BREQ pin is sampled at the T
(4) The BACK pin is returned to the High level, ending the bus-right release cycle.
* T
ø
A
D –D
RD, WR
R/W, DS
BREQ
BACK
T
19
7
I
X
: Internal CPU operation state.
–A
: Bus-right released state.
0
0
Figure 3-15 Bus-Right Release Cycle (During Internal CPU Operation)
T
i
*
External access cycle
T
i
(1)
T
i
X
state and a High level is detected.
T
i
75
I
Fig. 3-15
state and the Low level is detected.
(2)
T
X
*
Bus-right release cycle
(3)
T
X
T
X
(4)
T
CPU cycle
1