20.2.5.2 ISP through COM Port
Features
The ‘ISP code’ for this mechanism is provided by Megawin.
Auto baudrate detection & operation independent of the oscillator frequency.
No additional hardware except an RS232 transceiver.
This ISP mechanism connects the target MCU to the PC through the COM port, which needs no additional
hardware except an RS232 transceiver chip (such as the MAX232 chip).
The following system diagram shows the connection between the target MCU and the PC. Where, P3.0 and P3.1
function as the UART’s RXD and TXD, respectively; and they are connected to the PC’s COM port through the
MAX232 chip.
It is not recommended to adopt this mechanism for ISP because the modern computer, especially a notebook
computer, is not equipped with a COM port gradually.
Figure 20-9. System Diagram for ISP via COM Port
Target System
PC
RS232 Transceiver
(such as MAX232)
MPC82G516A
5
4
3
2
1
9
8
7
6
COM Port
RS232 Cable
TXD
RXD
P3.1
P3.0
T_IN
T_OUT
R_IN
R_OUT
With
Megawin
-provided
'ISP code'
RS232
Connector
preprogrammed
in the
ISP-memory
MEGAWIN
MPC82G516A Data Sheet
106
MEGAWIN [ MEGAWIN TECHNOLOGY CO., LTD ]
