DM-COP8/20D National Semiconductor, DM-COP8/20D Datasheet - Page 47

• Manufacturer Part Number: DM-COP8/20D
• Description: CABLE FOR DEBUG MODULE 20-DIP
• Manufacturer: National Semiconductor

Specifications of DM-COP8/20D

• Accessory Type: 20-DIP Target Cable
• For Use With/related Products: MetaLink Debug Module
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: *DM-COP8/20D

Port G is an 8-bit port. Pin G0, G2-G5 are bi-directional I/O ports. Pin G6 is always a
general purpose Hi-Z input. All pins have Schmitt Triggers on their inputs. Pin G1
serves as the dedicated WDOUT WATCHDOG output with weak pullup if
WATCHDOG feature is selected by the ECON register. The pin is a general
purpose I/O if WATCHDOG feature is not selected. If WATCHDOG feature is
selected, bit 1 of the Port G configuration and data register does not have any effect on
Pin G1 setup. Pin G7 is either input or output depending on the oscillator option selected.
With the crystal oscillator option selected, G7 serves as the dedicated output pin for the CKO
clock output. With the internal R/C or the external oscillator option selected, G7 serves as a
general purpose Hi-Z input pin and is also used to bring the device out of HALT mode with a
low to high transition on G7. There are two registers associated with Port G, a data register
and a configuration register. Using these registers, each of the 5 I/O pins (G0, G2-G5) can be
individually configured under software control.
Since G6 is an input only pin and G7 is the dedicated CKO clock output pin (crystal clock
option) or general purpose input (R/C or external clock option), the associated bits in the
data and configuration registers for G6 and G7 are used for special purpose functions as
outlined below. Reading the G6 and G7 data bits will return zeros.
The device will be placed in the HALT mode by writing a “1” to bit 7 of the Port G Data
Register. Similarly the device 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 MICROWIRE/
PLUS to operate with the alternate phase of the SK clock. The G7 configuration bit, if set
high, enables the clock start up delay after HALT when the R/C clock configuration is
used.
G7
G6
N
N
N
R
R
R
N
N
N
U
U
T
T
T
E
E
E
A
A
A
B
B
B
S
S
L
L
L
I
I
I
Figure 2-4 I/O Port Configurations
PORT L, G, AND C, F
PORT L, G, AND C, F
PORT L, G, AND C, F
Port read into a RAM address location
CLKDLY
Alternate SK
Config Reg.
CONFIGURATION
REGISTER
REGISTER
REGISTER
REGISTER
DATA
DATA
DATA
HALT
IDLE
Data Reg.
COP8SAx7 MICROCONTROLLER
V
CC
Weak
Pullup
(Software
Selectable)
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