HD6435348R Hitachi Semiconductor, HD6435348R Datasheet - Page 482

• Manufacturer Part Number: HD6435348R
• Description: Single-Chip Microcomputer
• Manufacturer: Hitachi Semiconductor

4. Mode 4
Figure E-4 shows how the pin states change when the RES pin goes Low during external memory
access in mode 4.
As soon as RES goes Low, all ports are initialized to the input (high-impedance) state. The AS,
DS, RD, and WR signals all go High. The data bus (D
state. Pins P5
bus are initialized as input ports.
7
/A
P1 / ø*
RES
Internal reset signal
A
R/W
AS, RD and DS (read)
WR and DS (write)
D to D (write)
I/O ports
*
19
7
The dotted line indicates that P1 /ø is an input port if the corresponding DDR bit is 0,
but a clock output pin if the DDR bit is 1.
0
15
to A
to P5
0
0
Figure E-3 Reset during Memory Access (Mode 3)
0
/A
8
of the address bus and pins P6
0
T
1
External memory
access
472
T
2
7
to D
3
0
) is placed in the high-impedance
/A
19
to P6
H’00000
High impedance
High impedance
0
/A
16
of the page address