HD6435348R Hitachi Semiconductor, HD6435348R Datasheet - Page 161

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

9.2 Port 1
9.2.1 Overview
Port 1 is an 8-bit input/output port with the pin configuration shown in figure 9-1. All pins have
dual functions, except that in the single-chip mode pins 4, 3, and 2 do not have the WAIT, BREQ,
and BACK functions (because the CPU does not access an external bus).
Outputs from port 1 can drive one TTL load and a 90 pF capacitive load. They can also drive a
Darlington transistor pair.
9.2.2 Port 1 Registers
Register Configuration: Table 9-2 lists the registers of port 1.
Table 9-2 Port 1 Registers
Name
Port 1 data direction register
Port 1 data register
System control register 1
*1 Bits 1 and 0 are read-only.
*2 Bits 1 and 0 are undetermined. Other bits are initialized to 0.
Port
1
Pin
P1
P1
ADTRG
P1
P1
P1
P1
P1
P1
7
6
5
4
3
2
1
0
/ TMO
/ IRQ
/ IRQ
/ WAIT
/ BREQ P1
/ BACK P1
/ E
/ ø
1
0
/ P1
Expanded Modes
P1
ADTRG (input)
P1
P1
P1
P1
7
6
5
4
3
2
1
0
Figure 9-1 Pin Functions of Port 1
Abbreviation
P1DDR
P1DR
SYSCR1
(input/output) / TMO (output)
(input/output) / IRQ
(input/output) / IRQ
(input/output) / WAIT (input)
(input/output) / BREQ (input)
(input/output) / BACK (output) P1
(input) / E (output)
(input) / ø (output)
144
Read/Write
W
R/W
R/W
1
0
(input) /
(input)
*1
Single-Chip Mode
P1
P1
ADTRG (input)
P1
P1
P1
P1
P1
7
6
5
4
3
2
1
0
Initial Value
H'03
Undetermined
H'87
(input/output) / TMO (output)
(input/output) / IRQ
(input/output) / IRQ
(input/output)
(input/output)
(input/output)
(input) / E (output)
(input) / ø (output)
*2
Address
H'FE80
H'FE82
H'FEFC
1
0
(input) /
(input)