Renesas RZB-ZMD16C-ZDK user manual System Operation & Limitations, Kernel ROM Monitor Introduction

Applications Engineering

7.0 System Operation & Limitations

The RZB-ZMD16C-ZDK provides sophisticated debugging features at a low cost, but it does have some limitations when used with the debugger and ICD. Section 6.1 introduces the kernel (ROM monitor) program and its purpose. The limitations when this kernel is running with the user program are listed in Table 7-1.

Table 7-1: System Limitations when Debugging

Item		Please Refer To
	7.2	Pin and Peripheral Limitations
User Limitations	7.3 Memory Map
	7.4 Register Operation Limitations
	7.5	Limitations on Interrupts - Vectors that Reside in the Hardware
	Vector Table
Debugger Limitations	7.6	Stop or Wait Mode Limitations
	7.7	User Program’s Real-Time Capability

7.1. Kernel (ROM Monitor) Introduction

During debug, a small program called a kernel is uploaded to the M16C/28. The kernel communicates with HEW through the ICD regarding MCU status during user code debugging operations.

There are no special steps required in the user program to make use of the ICD. The operation of the kernel is transparent to the user, but there are some limitations. These are discussed from section 7.2 onward.

After starting a HEW debug session, the ICD uploads the kernel to the M16C/28 if it does not exist (e.g. a blank device or a device that was programmed with the FoUSB Programmer). After downloading the kernel, the M16C/28 is ready to download user code.

Connecting the ICD without starting HEW will not affect the signal lines connected between the ICD and the M16C/28; the ICD keeps the signal lines in high-impedance state. The ICD only drives the pins after HEW or the FoUSB Programmer attempts to connect.

After completing program debug and verification with HEW, you can create an image of your code in Intel (.hex) or Motorola (.mot) file formats. This image can be programmed into the M16C/28 using the FoUSB Programmer. This procedure erases the kernel and leaves only the user program.

7.2. Pin and Peripheral Limitations

SIO/UART1 pins are used for communication between the M16C/28 kernel on the RZB-ZMD16C-ZDK board and HEW through the ICD. Do not connect these pins to any other circuit, as UART1 cannot be used in the user program while using the Debugger. For details, please see the RTA-FoUSB-MON (ICD) User’s Manual on Target M16C ROM Monitor Resources or related ICD application notes.

7.3. Memory Map

The amount and locations of memory used by the kernel on the RZB-ZMD16C-ZDK board’s M16C/28 MCU are shown in Figure 7-1.

RZB-ZMD16C-ZDK User’s Manual Rev 1.2 17/ 33 August 2006