COP688CL datasheet(11/40 Pages) NSC

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AC Electrical Characteristics (Continued)

TLDD9766 – 26

FIGURE 2 MICROWIREPLUS Timing

Pin Descriptions

VCC and GND are the power supply pins

CKI is the clock input This can come from an RC generat-

ed oscillator or a crystal oscillator (in conjunction with

CKO) See Oscillator Description section

RESET is the master reset input See Reset Description

section

The device contains three bidirectional 8-bit IO ports (C G

and L) where each individual bit may be independently con-

figured as an input (Schmitt trigger inputs on ports G and L)

output or TRI-STATE under program control Three data

memory address locations are allocated for each of these I

O ports Each IO port has two associated 8-bit memory

mapped registers the CONFIGURATION register and the

output DATA register A memory mapped address is also

reserved for the input pins of each IO port (See the memo-

ry map for the various addresses associated with the IO

ports)

Figure 3 shows the IO port configurations The

DATA and CONFIGURATION registers allow for each port

bit to be individually configured under software control as

shown below

CONFIGURATION

DATA

Port Set-Up

Hi-Z Input

(TRI-STATE Output)

Input with Weak Pull-Up

Push-Pull Zero Output

Push-Pull One Output

TLDD9766 – 6

FIGURE 3 IO Port Configurations

PORT L is an 8-bit IO port All L-pins have Schmitt triggers

on the inputs

Port L supports Multi-Input Wakeup (MIWU) on all eight

pins L4 and L5 are used for the timer input functions T2A

and T2B

Port L has the following alternate features

MIWU

MIWU or T2A

MIWU or T2B

MIWU

Port G is an 8-bit port with 5 IO pins (G0 G2 – G5) an input

pin (G6) and two dedicated output pins (G1 and G7) Pins

G0 and G2 – G6 all have Schmitt Triggers on their inputs Pin

G1 serves as the dedicated WDOUT WATCHDOG output

while pin G7 is either input or output depending on the oscil-

lator mask option selected With the crystal oscillator option

selected G7 serves as the dedicated output pin for the CKO

clock output With the single-pin RC oscillator mask option

selected G7 serves as a general purpose input pin but is

also used to bring the device out of HALT mode with a low

to high transition There are two registers associated with

the G Port a data register and a configuration register

Therefore each of the 5 IO bits (G0 G2 – G5) can be indi-

vidually configured under software control

Since G6 is an input only pin and G7 is the dedicated CKO

clock output pin or general purpose input (RC clock config-

uration) the associated bits in the data and configuration

registers for G6 and G7 are used for special purpose func-

tions as outlined below Reading the G6 and G7 data bits

will return zeros

Note that the chip will be placed in the HALT mode by writ-

ing a ‘‘1’’ to bit 7 of the Port G Data Register Similarly the

chip will be placed in the IDLE mode by writing a ‘‘1’’ to bit 6

of the Port G Data Register

Writing a ‘‘1’’ to bit 6 of the Port G Configuration Register

enables the MICROWIREPLUS to operate with the alter-

nate phase of the SK clock The G7 configuration bit if set

high enables the clock start up delay after HALT when the

RC clock configuration is used

Config Reg

Data Reg

CLKDLY

HALT

Alternate SK

IDLE

Port G has the following alternate features

INTR (External Interrupt Input)

T1B (Timer T1 Capture Input)

T1A (Timer T1 IO)

SO (MICROWIRETM Serial Data Output)

SK (MICROWIRE Serial Clock)

SI (MICROWIRE Serial Data Input)

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