How to make on board debug V1.1
Chapter 4 Hardware Design
MCU-AN- 500018-E-11 – Page 7
4 Hardware Design
This chapter introduces the circuit of debugging interface.
As the MB95200 series has two types of flash, i.e. single flash and dual flash, there are two
types of debugging circuits corresponding to them. This chapter will introduce the two
programming circuits. Make sure to choose the correct circuit in application.
4.1 Single Flash MCU Debugging Circuit
Figure 4-1 shows the circuit diagram of the in-system debugging interface. To design the in-
system debugging interface, four pins, UVCC_EV, GND, RSTIN and DBG, are needed. (Add
pin RST_OUT if necessary).
.
Figure 4-1 Basic Connector Circuit for Single Flash MCU
Component Recommendation:
D1: VF < 0.3V when IF = 1mA. E.g. LL103A, 1SS294.
Below is a list of functions of the interface connector.
(1) J1 is a 10-pin connector, used as the circuit interface.
(2) The write voltage (VCC = 4.5V to 5.5V) is supplied from the user system. The UVCC_EV
and DBG pins control the PGM mode entry.
(3) Pin 2 of the connector connects to the GND.
(4) The debugger provides 10 V directly to the RSTX pin during flash erase/write operation.
If it is pulled high in the user system, please consider to add a low-drop diode for
separate H voltage.
(5) The DBG pin provides 1-line UART communication with the debugger. Serial write mode
can be set by providing special timing of DBG and VCC pins.
Target Board
