MC68HC908GZ8MFA Freescale Semiconductor, MC68HC908GZ8MFA Datasheet - Page 131

• Manufacturer Part Number: MC68HC908GZ8MFA
• Description: IC MCU 8K FLASH 8MHZ CAN 48-LQFP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC68HC908GZ8MFA

• 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
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

12.8.1 MSCAN08 Sleep Mode
The CPU can request the MSCAN08 to enter the low-power mode by asserting the SLPRQ bit in the
module configuration register (see
depends on its activity:
During sleep mode, the SLPAK flag is set. The application software should use SLPAK as a handshake
indication for the request (SLPRQ) to go into sleep mode. When in sleep mode, the MSCAN08 stops its
internal clocks. However, clocks to allow register accesses still run. If the MSCAN08 is in bus-off state, it
stops counting the 128*11 consecutive recessive bits due to the stopped clocks. The CAN
recessive state. If RXF = 1, the message can be read and RXF can be cleared. Copying of RxGB into
RxFG doesn’t take place while in sleep mode. It is possible to access the transmit buffers and to clear the
TXE flags. No message abort takes place while in sleep mode.
The MSCAN08 leaves sleep mode (wakes-up) when:
Freescale Semiconductor
•
•
•
•
•
•
If it is transmitting, it continues to transmit until there is no more message to be transmitted, and
then goes into sleep mode
If it is receiving, it waits for the end of this message and then goes into sleep mode
If it is neither transmitting or receiving, it will immediately go into sleep mode
Bus activity occurs, or
The MCU clears the SLPRQ bit, or
The MCU sets the SFTRES bit
1. ‘X’ means don’t care.
The application software must avoid setting up a transmission (by clearing
or more TXE flags) and immediately request sleep mode (by setting
SLPRQ). It then depends on the exact sequence of operations whether
MSCAN08 starts transmitting or goes into sleep mode directly.
The MCU cannot clear the SLPRQ bit before the MSCAN08 is in sleep
mode (SLPAK=1).
MSCAN08 Mode
Power Down
Soft Reset
Normal
Sleep
Table 12-2. MSCAN08 versus CPU Operating Modes
MC68HC908GZ16 • MC68HC908GZ8 Data Sheet, Rev. 4
Figure
12-7). The time when the MSCAN08 enters sleep mode
SLPAK = X
SFTRES = X
NOTE
NOTE
STOP
.
(1)
CPU Mode
WAIT or RUN
SFTRES = 0
SFTRES = 1
SFTRES = 0
SLPAK = 1
SLPAK = 0
SLPAK = 0
Low-Power Modes
TX
pin stays in
131