HD6475328-CP10 Datasheet, PDF (159/459 Pages) Hitachi Semiconductor – original Hitachi CMOS microcomputer unit (MCU)

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 90pF capacitive load. They can also drive a
Darlington transistor pair.
Pin
Expanded Modes
Single-Chip Mode
P17 / TMO P17 (input/output) / TMO (output) P17 (input/output) / TMO (output)
P16 / IRQ1 P16 (input/output) / IRQ1 (input) P16 (input/output) / IRQ1 (input)
P15 / IRQ0 P15 (input/output) / IRQ0 (input) P15 (input/output) / IRQ0 (input)
Port
P14 / WAIT P14 (input/output) / WAIT (input) P14 (input/output)
1
P13 / BREQ P13 (input/output) / BREQ (input) P13 (input/output)
P12 / BACK P12 (input/output) / BACK (output) P12 (input/output)
P11 / E
P11 (input) / E (output)
P11 (input) / E (output)
P10 / ø
P10 (input) / ø (output)
P10 (input) / ø (output)
Figure 9-1 Pin Functions of Port 1
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
Port 1 control register
Abbreviation
P1DDR
P1DR
P1CR
Read/Write
W
R/W^*1
R/W
Initial Value
H'03
Undetermined^*2
H'87
Address
H'FF80
H'FF82
H'FFFC
*1 Bits 1 and 0 are read-only.
*2 Bits 1 and 0 are undetermined. Other bits are initialized to “0.”
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