cop888gw National Semiconductor Corporation, cop888gw Datasheet - Page 6

• Manufacturer Part Number: cop888gw
• Description: 8-bit Microcontroller With Pulse Train Generators And Capture Modules
• Manufacturer: National Semiconductor Corporation

www.national.com
Pin Descriptions
V
pins must be connected.
CKI is the clock input. This comes from an R/C generated
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 five bidirectional 8-bit I/O ports (C, E, F,
G and L), where each individual bit may be independently
configured as an input (Schmitt trigger inputs on ports L and
G), output or TRI-STATE under program control. Three data
memory address locations are allocated for each of these
I/O ports. Each I/O 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 I/O port. (See the memory
map for the various addresses associated with the I/O ports.)
Figure 3 shows the I/O port configurations. The DATA and
CONFIGURATION registers allow for each port bit to be
individually configured under software control as shown be-
low:
CC
Configuration
and GND are the power supply pins. All V
Register
0
0
1
1
Register
Data
0
1
0
1
Hi-Z Input
(TRI-STATE Output)
Input with Weak Pull-Up
Push-Pull Zero Output
Push-Pull One Output
Port Set-Up
CC
and GND
6
PORT L is an 8-bit I/O port. All L-pins have Schmitt triggers
on the inputs.
The Port L supports Multi-Input Wake Up on all eight pins. L1
is used for the UART external clock. L2 and L3 are used for
the UART transmit and receive. L4 and L5 are used for the
timer input functions T2A and T2B. L6 and L7 are used for
the capture timer input functions CAP1 and CAP2.
The Port L has the following alternate features:
Port G is an 8-bit port with 6 I/O pins (G0–G5), an input pin
(G6), and a dedicated output pin (G7). Pins G0–G6 all have
Schmitt Triggers on their inputs. Pin G7 serves as the dedi-
cated output pin for the CKO clock output. There are two
registers associated with the G Port, a data register and a
configuration register. Therefore, each of the 6 I/O bits
(G0–G5) can be individually configured under software con-
trol.
L0 MIWU
L1 MIWU or CKX
L2 MIWU or TDX
L3 MIWU or RDX
L4 MIWU or T2A
L5 MIWU or T2B
L6 MIWU or CAP1
L7 MIWU or CAP2