mc68hc908gr8a Freescale Semiconductor, Inc, mc68hc908gr8a Datasheet - Page 77

• Manufacturer Part Number: mc68hc908gr8a
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

LVI5OR3 — LVI 5-V or 3-V Operating Mode Bit
SSREC — Short Stop Recovery Bit
STOP — STOP Instruction Enable Bit
COPD — COP Disable Bit
Freescale Semiconductor
LVI5OR3 selects the voltage operating mode of the LVI module (see
(LVI)). The voltage mode selected for the LVI should match the operating V
Electrical
SSREC enables the CPU to exit stop mode with a delay of 32 CGMXCLK cycles instead of a
4096-CGMXCLK cycle delay.
If the system clock source is an external crystal and the OSCSTOPENB configuration bit is not set, the
oscillator will be disabled during stop mode. The short stop recovery does not provide enough time for
oscillator stabilization and for this reason the SSREC bit should not be set.
The system stabilization time for power-on reset and long stop recovery (both 4096 CGMXCLK cycles)
gives a delay longer than the LVI enable time for these startup scenarios. There is no period where the
MCU is not protected from a low-power condition. However, when using the short stop recovery
configuration option, the 32-CGMXCLK delay must be greater than the LVI’s turn on time to avoid a
period in startup where the LVI is not protecting the MCU.
STOP enables the STOP instruction.
COPD disables the COP module. See
1 = LVI operates in 5-V mode
0 = LVI operates in 3-V mode
1 = Stop mode recovery after 32 CGMXCLK cycles
0 = Stop mode recovery after 4096 CGMXCLCK cycles
1 = STOP instruction enabled
0 = STOP instruction treated as illegal opcode
1 = COP module disabled
0 = COP module enabled
Specifications) for the LVI’s voltage trip points for each of the modes.
The LVI5OR3 bit is cleared by a power-on reset (POR) only. Other resets
will leave this bit unaffected.
Exiting stop mode by an LVI reset will result in the long stop recovery.
MC68HC908GR8A • MC68HC908GR4A Data Sheet, Rev. 5
Chapter 6 Computer Operating Properly (COP)
NOTE
NOTE
Chapter 11 Low-Voltage Inhibit
DD
(see
Functional Description
Chapter 19
Module.
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