HD6433045 HITACHI [Hitachi Semiconductor], HD6433045 Datasheet - Page 262

• Manufacturer Part Number: HD6433045
• Description: Hitachi Single-Chip Microcomputer
• Manufacturer: HITACHI [Hitachi Semiconductor]

9.3 Port 2
9.3.1 Overview
Port 2 is an 8-bit input/output port with the pin configuration shown in figure 9-2. The pin
functions differ according to the operating mode.
In modes 1 to 4 (expanded modes with on-chip ROM disabled), port 2 consists of address bus
output pins (A
in the port 2 data direction register (P2DDR) can designate pins for address bus output (A
or generic input. In mode 7 (single-chip mode), port 2 is a generic input/output port.
When DRAM is connected to area 3, A
write cycles. For details see section 7, Refresh Controller.
Port 2 has software-programmable built-in pull-up MOS. Pins in port 2 can drive one TTL load
and a 90-pF capacitive load. They can also drive a darlington transistor pair.
Port 2
15
to A
8
Port 2 pins
). In modes 5 and 6 (expanded modes with on-chip ROM enabled), settings
P2 /A
P2 /A
P2 /A
P2 /A
P2 /A
P2 /A
P2 /A
P2 /A
7
6
5
4
3
2
1
0
15
14
13
12
11
10
9
8
Figure 9-2 Port 2 Pin Configuration
Modes 1 to 4
A
A
A
A
A
A
A (output)
A (output)
15
14
13
12
11
10
9
8
9
(output)
(output)
(output)
(output)
(output)
(output)
and A
8
249
output row and column addresses in read and
Modes 5 and 6
P2 (input)/A
P2 (input)/A
P2 (input)/A
P2 (input)/A
P2 (input)/A
P2 (input)/A
P2 (input)/A
P2 (input)/A
7
6
5
4
3
2
1
0
15
14
13
12
11
10
9
8
(output)
(output)
(output)
(output)
(output)
(output)
(output)
(output)
Mode 7
P2 (input/output)
P2 (input/output)
P2 (input/output)
P2 (input/output)
P2 (input/output)
P2 (input/output)
P2 (input/output)
P2 (input/output)
7
6
5
4
3
2
1
0
15
to A
8
)