NXP Semiconductors MC908QY8CDWE

Overview

MC908QY8CDWE from Freescale Semiconductor is an 8-bit M68HC08 core microcontroller with 8 KB on-chip FLASH, 256 B RAM, 10-bit ADC (8-channel), ESCI and SPI serial interfaces, and integrated oscillator. It operates at up to 8 MHz bus frequency and supports low-power wait/stop modes for battery-powered sensor and control applications.

For engineers reviewing the MC908QY8CDWE datasheet, MC908QY8CDWE pinout, MC908QY8CDWE application, or MC908QY8CDWE equivalent, key selection criteria include its 20-pin SOIC-W package, FLASH security byte validation ($FFF6–$FFFD), COP watchdog timing, AWU wake-on-external-event capability, and compatibility with HC08 development tools including P&E Multilink and CodeWarrior IDE.

Technical Context

The MC908QY8CDWE implements the M68HC08 CPU core with 16-bit address space, supporting indexed, extended, and relative addressing. Its memory map includes 8 KB FLASH (with page/mass erase and block protection), 256 B RAM, and 64 B EEPROM-like configuration registers. The internal oscillator supports trimming via register OSCCTL for ±2% accuracy across voltage and temperature.

Peripherals include a 10-bit ADC with programmable sample time and conversion trigger sources (software, timer, external edge), ESCI supporting asynchronous UART and LIN 1.3, and SPI master/slave mode with independent clock polarity and phase control. Security enforcement requires eight user-defined bytes at $FFF6–$FFFD; monitor mode entry is denied if five or more are zero.

Key Specifications

Pinout & Package

MC908QY8CDWE is housed in a 20-pin SOIC-W (wide-body) package with 0.600-inch body width and 0.050-inch lead pitch. Pinout conforms to standard HC08 QY8 pin assignment per Rev. 3 datasheet.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit microcontroller applications.

Compared with MC908QY4CDWE and MC908QY8CPBE, the MC908QY8CDWE uniquely balances industrial SOIC-W packaging, full LIN-capable ESCI, and 8 KB FLASH for field-upgradable firmware - making it optimal for cost-sensitive, volume-manufactured embedded controllers requiring long-term reliability and protocol compliance.

Availability

MC908QY8CDWE is available at Aetrix Electronics and suitable for industrial sensor nodes, home appliance control systems, automotive body modules, and legacy PLC I/O expansion requiring stable component supply and long-lifecycle support.

Supply support for MC908QY8CDWE includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Freescale Semiconductor (now part of NXP Semiconductors) pioneered mixed-signal microcontrollers for automotive, industrial, and consumer markets with robust design-for-manufacturing and long-term product roadmaps.

The MC908QY8CDWE belongs to the M68HC08 family, designed specifically for cost-sensitive, low-power embedded control applications where small footprint, integrated peripherals, and field-programmable FLASH security are critical.

FAQ

What is the maximum operating frequency of the MC908QY8CDWE?

The MC908QY8CDWE supports a maximum bus frequency of 8 MHz when powered at 4.5–5.5 V. This frequency is derived from the internal oscillator (trimmed via OSCCTL) or an external crystal up to 8 MHz. The CPU executes instructions at one-quarter bus speed (2 MHz instruction rate), consistent with M68HC08 architecture timing. All electrical specifications in the Rev. 3 datasheet assume operation within this validated range.

How does the FLASH security feature work on the MC908QY8CDWE?

The MC908QY8CDWE implements FLASH security by requiring eight user-defined bytes programmed into memory locations $FFF6–$FFFD. During monitor mode entry, the host must send matching bytes; if five or more are $00, monitor access is denied. This prevents unauthorized firmware readout while allowing legitimate debug access. The MC908QY8CDWE datasheet explicitly warns against leaving these locations unprogrammed for security reasons.

Which ADC channels are available on the MC908QY8CDWE and how are they mapped?

The MC908QY8CDWE provides eight 10-bit ADC input channels (AD0–AD7). Channels AD0–AD3 are multiplexed onto Port A pins PA0–PA3; AD4–AD7 are available on dedicated analog input pins PTA0–PTA3. Channel selection is controlled via the ADSCR register. Input voltage range is 0–VREFH, with VREFH and VREFL configurable externally or internally tied to VDD/VSS.

Does the MC908QY8CDWE support LIN 1.3 communication?

Yes, the MC908QY8CDWE supports LIN 1.3 communication via its Enhanced Serial Communications Interface (ESCI) module. The ESCI implements hardware-level LIN break detection, synchronization field handling, and checksum generation/validation per LIN specification. This capability is confirmed in Chapter 13 of the MC68HC908QB8/QY8 datasheet and applies identically to the MC908QY8CDWE variant.

What low-power modes does the MC908QY8CDWE support and how are they entered?

The MC908QY8CDWE supports Wait and Stop low-power modes. Wait mode halts the CPU while keeping clocks active for peripherals like ADC and timers; entered via WAI instruction. Stop mode disables all clocks except AWU and IRQ sources; entered via STOP instruction. Both modes are exited by IRQ, KBI, or AWU events. The MC908QY8CDWE's LVI and COP modules remain functional in both modes to ensure safe operation during voltage transients or firmware hangs.