Remote-processing RPC-220 Bedienungsanleitung PDF herunterladen (Seite 30)

COUNTER/TIMERS SECTION 8

Page 8-1

Name Timing

function

1 P1.0 CTOI

2 P4.3 CMSR3

3 P1.1 CT1I

4 RTC Square wave

5 P1.2 CT2I

6 P3.2 T0 gate

7 P1.3 CT3I

8 +5V

9 P1.4 T2 clock

10 Reset

11 P1.5 T2 reset

12 Ground

13 P4.5 CMSR5

14 Ground

15 P1 .6

16 P4.4 CMSR4

17 P1.7

18 +5V

19 P3.4 T0 clock

20 PWM1

21 P3.5 T1 clock

22 PWM0

23 P3.3 T1 gate

24 P4.6 CMT0

25 RTC IRQ

26 P4.7 CMT1

Table 8-1 J3 timing pins

INTRODUCTION

COUNTER/TIMERS SECTION 8

The 80C552 CPU chip on the RPC -220 has many

counter/timers. These ar e used to count pulses or

measur e pulse widths. Some of thes e timer s are multi-

purpose, and are shared with other functions. Timer 1 is

used as the baud rate generator for COM 0. Some lines

used for timing are also used for other functions, such as

LCD display and softw are ser ial port.

The optional RTC can generate periodic interrupts on

INT1. See SECTION 7, INTERRUPTS for more

information.

Timer operation is described in detail in two PDF files.

FAM HDW R.P DF describes timers 0 and 1 and

8XC552OV .P DF descr ibes timer 2. Review the

application programs listed at the end of this section.

Timers 0 and 1 operate the same as on the 80C51 CPU.

TIMER 0

Timers 0 and 1 are very similar to each other. Since the

serial port is used for most applications, timer 1 is not

described.

Timer 0 uses an external or internal clock. When

operating on an external clock, it is effectively a counter.

Pulses go into port P3.4, available at J3-19. Pulses are

gated by the T CON and TM OD r egisters an d INT 0 pin

on J3-6 and J2-6. These pins have "soft" pull ups and

may require external resistors to operate reliably.

Maximum clock frequency to timer 0 is 921.6 Khz and

the minimum pulse width is 542 nano-seconds. The

timers operate in one of 4 modes and generate an

interrupt on a terminal count. Refer to the

FAM HDW R.P DF file for a complete description of

these modes.

J3 CONNECTOR PIN OUT

The table below is the pin out for J3 and associated

timing and alternate functions.

1 2 ... 25 26 27 28 29 30 31 32 33 34 35 ... 46 47

Kommentare zu diesen Handbüchern

Keine Kommentare

Remote-processing RPC-220 Bedienungsanleitung Seite 30

Kommentare zu diesen Handbüchern

Verwandte Produkte und Handbücher für Computers Remote-processing RPC-220