MC68908GZ8MFAE Freescale Semiconductor, MC68908GZ8MFAE Datasheet - Page 133

• Manufacturer Part Number: MC68908GZ8MFAE
• Description: IC MCU 8BIT 8K FLASH 48-LQFP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC68908GZ8MFAE

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: CAN, LIN, SCI, SPI
• Peripherals: LVD, POR, PWM
• Number Of I /o: 37
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 48-LQFP
• Processor Series: M689xx
• Core: HC08
• Data Bus Width: 8 bit
• Data Ram Size: 1 KB
• Interface Type: SPI, SCI, CAN
• Maximum Clock Frequency: 8 MHz
• Number Of Programmable I/os: 37
• Number Of Timers: 2
• Operating Supply Voltage: 5.5 V
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Development Tools By Supplier: FSICEBASE, M68CBL05AE, DEMO908GZ60E, M68EML08GZE
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 16 Channel
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

Timer Link
To protect the CAN bus system from fatal consequences resulting from violations of the above rule, the
MSCAN08 drives the CAN
pin into recessive state.
TX
In power-down mode, no registers can be accessed.
MSCAN08 bus activity can wake the MCU from CPU stop/MSCAN08 power-down mode. However, until
the oscillator starts up and synchronization is achieved the MSCAN08 will not respond to incoming data.
12.8.4 CPU Wait Mode
The MSCAN08 module remains active during CPU wait mode. The MSCAN08 will stay synchronized to
the CAN bus and generates transmit, receive, and error interrupts to the CPU, if enabled. Any such
interrupt will bring the MCU out of wait mode.
12.8.5 Programmable Wakeup Function
The MSCAN08 can be programmed to apply a low-pass filter function to the CAN
input line while in
RX
internal sleep mode (see information on control bit WUPM in
12.13.2 MSCAN08 Module Control Register
1). This feature can be used to protect the MSCAN08 from wakeup due to short glitches on the CAN bus
lines. Such glitches can result from electromagnetic inference within noisy environments.
12.9 Timer Link
The MSCAN08 will generate a timer signal whenever a valid frame has been received. Because the CAN
specification defines a frame to be valid if no errors occurred before the EOF field has been transmitted
successfully, the timer signal will be generated right after the EOF. A pulse of one bit time is generated.
As the MSCAN08 receiver engine also receives the frames being sent by itself, a timer signal also will be
generated after a successful transmission.
The previously described timer signal can be routed into the on-chip timer interface module (TIM). This
signal is connected to channel 0 of timer interface module 1 (TIM1) under the control of the timer link
enable (TLNKEN) bit in CMCR0.
After the timer has been programmed to capture rising edge events, it can be used under software control
to generate 16-bit time stamps which can be stored with the received message.
12.10 Clock System
Figure 12-8
shows the structure of the MSCAN08 clock generation circuitry and its interaction with the
clock generation module (CGM). With this flexible clocking scheme the MSCAN08 is able to handle CAN
bus rates ranging from 10 kbps up to 1 Mbps.
The clock source bit (CLKSRC) in the MSCAN08 module control register (CMCR1) (see
12.13.1
MSCAN08 Module Control Register
0) defines whether the MSCAN08 is connected to the output of the
crystal oscillator or to the PLL output.
The clock source has to be chosen such that the tight oscillator tolerance requirements (up to 0.4%) of
the CAN protocol are met.
MC68HC908GZ16 • MC68HC908GZ8 Data Sheet, Rev. 4
Freescale Semiconductor
133