z16f2811 ZiLOG Semiconductor, z16f2811 Datasheet - Page 310

• Manufacturer Part Number: z16f2811
• Description: High Performance Microcontrollers
• Manufacturer: ZiLOG Semiconductor

Operation
PS022006-0207
Caution:
On-Chip Debug Enable
Serial Interface
The DBG pin is mainly used for debugging. The OCD is always enabled by default
following reset. Disable the OCD after startup and use the DBG pin as a UART or a GPIO
pin if the
To use the DBG pin as a UART or GPIO pin, the OCD must be disabled. The OCD is
disabled by clearing the OCDEN bit in the Debug
cannot be disabled, if the OCDLOCK bit in the DBGCTL register is set.
The DBG pin is used for serial communication. This one-pin interface is a bidirectional
half-duplex open-drain interface that transmits and receives data. Transmit and receive
operations cannot occur simultaneously. The serial data is sent and received using the
asynchronous protocol defined in RS-232. The serial pin is connected to the serial port of
the PC using minimal external hardware. Two different methods for connecting the serial
pin to an RS-232 interface are depicted in
The serial pin is open-drain and must be connected to V
resistor to ensure proper operation.
Figure 62. Interfacing the serial pin with an RS-232 Interface (1)
RS232 TX
RS232 RX
For effective operation of the device, all power pins (V
supplied with power, and all ground pins (V
grounded. The DBG pin must be connected to V
resistor to ensure proper operation.
DBGUART
option bit has been cleared.
RS-232
Tranceiver
P R E L I M I N A R Y
Diode
Figure 62
Vdd
10 kOhm
Control Register
SS
and
and AV
DD
DBG pin
DD
Figure
through an external pull-up
through an external pull-up
SS
DD
63.
Product Specification
) must be properly
ZNEO
and AV
(DBGCTL). The OCD
On-Chip Debugger
™
DD
Z16F Series
) must be
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