Freescale Semiconductor DRM079 manual Freescale’s New Generation Ultra Low Cost MCU

Introduction

1.2 Freescale’s New Generation Ultra Low Cost MCU

The MC9RS08KA2 microcontroller unit (MCU) is an extremely low cost, small pin count device for home appliances, toys, and small geometry applications, such as a DC fan controller. This device is composed of standard on-chip modules including a very small and highly efficient RS08 CPU core, 62 bytes RAM, 2K bytes FLASH, an 8-bit modulo timer, keyboard interrupt, and analog comparator. The device is available in small 6- and 8-pin packages.

Features of the MC9RS08KA2 include:

•8-bit RS08 core

–Up to 10 MHz (bus frequency) at 1.8V for 100 ns minimum instruction time

–RS08 instruction set

–Supports tiny/short address mode

–14-byte fast-access RAM

–Allows emulation of HC08/HCS08 zero-offset index addressing mode instructions

•Third-generation Flash and RAM (extremely fast, byte writable programming)

–63 Byte RAM

–2K Byte Flash

•Flexible clock options

•4 Bidirectional I/O lines with software selectable pull-up (eliminates need for external resistors)

•Analog comparator

•Real time interrupt

•8-bit timer with 8-bit prescale

•System protection

–Resets in instance of runaways or corrupted code

–Low voltage detection

–Illegal opcode and illegal address detection

–Flash security feature

•Single wire debugging and emulation interface; eliminates need for expensive emulation tools or development hardware

1.3 DC Fan Reference Design Targets

Table 1-1. Design Targets

	Item	Requirement
	Motor Type	Bi-phase BLDC motor
	Fan Dimensions	60mm x 60mm x 25mm
	Operating Voltage	12V
	Current Rating	0.18A (max.)
	Speed	1000 to 4000 RPM
	Temperature Feedback	Yes
	Fault Detection	Air flow blocking (motor jam)
	Fault Notification	Buzzer alarm
	Variable Speed DC Fan Control using the MC9RS08KA2, Rev. 0
8			Freescale Semiconductor