D E M O 9 0 8 L B 8
M A R C H 2 4 , 2 0 0 5
9
Figure 2: MON08 Debug Port
1
2
GND
3
4
PTA3/RST*
5
6
PTA2/IRQ*
See the HC08 Reference Manual for complete
MON08 documentation
7
8
PTA0
9
10
PTA4
11
12
PTA1
PTA5/OSC1
13
14
V
DD
15
16
DEBUG Connector
Serial MON08 access is provided through a standard 9-pin DSUB connector. An RS-232
translator provides RS-232 logic level to TTL/CMOS logic level translation on the DEBUG port.
The figure below shows the DB9 connector pin-out. The VTST_EN jumper must be installed
as the MCU exits RESET to invoke monitor mode. The MON_EN option jumper enables serial
MON08 access. The MCU supports monitor mode communications at 9600 bps. Refer to
MC68HC908LB8 documentation for further details.
Figure 3: DEBUG Connector
1
6
TXD
2
7
RTS
RXD
3
8
CTS
4
9
NC
GND
5
Female DB9 connector that interfaces to the HC08 internal SCI1 serial
port via the U2 RS232 transceiver. It provides simple 2 wire asynchro-
nous serial communications without flow control.
Pins 1, 4, and 6 are connected together for NULL status to the host
Pins 7, 8 are connected together for flow control if needed
MON08 Setup
The following figure shows the settings necessary to configure monitor mode operation. To
ensure seamless monitor mode entry, the user should remove the USER5 jumper as shown
below. The USER5 jumper enables the POT, which connects to monitor mode configuration
line PTA1. Failure to remove this jumper may prevent monitor mode entry.
Configure MON_EN jumper for the monitor mode access desired.
