TC9028AP Ver la hoja de datos (PDF) - Toshiba

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TC9028AP

TOSHIBA CMOS Digital Integrated Circuit Silicon Monolithic

Toshiba 

TC9028AP/AF

2.10.3 Instruction cycle

Instructions and internal hardware operations are executed in sync with the fundamental

clock. The minimum unit of instruction execution is called the instruction cycle. TC9028AP and

TC9028AF has 1 and 2-cycle instructions. An instruction cycle consists of 5 states (S0-S4). Each

state consists of 1 fundamental clock. Therefore, the instruction cycle time is 5/fc [s].

3. Peripheral hardware functions

3.1 Ports

The following functions are executed using I/O instructions (4 types):

key scan, send signal output, send display output, internal circuit control.

This system features the 2 types of ports listed below. Addresses (00-05H) are allocated to these ports:

(1) I/O ports: key scan, send signal output, send display output

(2) Command register: internal circuit control

Ports are selected by specifying port addresses with I/O instructions. The port register controls input

and output of programmable I/O ports.

3.1.1

Port register (PR)

The port register is a 4 bit write-only register. It is used for selecting input or output mode for

programmable I/O ports. Since an option is used to select input or output mode during hold, the

port register cannot select the mode.

Port register (PR)

3

2

1

0

 P2S P1HS P1LS

(Initial value: 0100)

Selects I/O mode for ports P2.

0: Input mode for P23~P20

1: Output mode for P23~P20

Selects I/O mode for port P1. (upper 2 bits)

0: Input mode for P13 and P12

1: Output mode for P13 and P12

Selects I/O mode for port P1 (lower 2 bits).

0: Input mode for P11 and P10

1: Output mode for P11 and P10

Figure 3.1 Programmable I/O port control using port register

8

2002-04-19

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