MC908QL4MDWE Freescale Semiconductor, MC908QL4MDWE Datasheet - Page 123

• Manufacturer Part Number: MC908QL4MDWE
• Description: IC MCU 8BIT 4K FLASH 16-SOIC
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC908QL4MDWE

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: LIN (Local Interconnect Network)
• Peripherals: LVD, POR, PWM
• Number Of I /o: 13
• Program Memory Size: 4KB (4K x 8)
• Program Memory Type: FLASH
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 6x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 16-SOIC (0.300", 7.5mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

SIM counter counts out 4096 BUSCLKX4 cycles after V
cycles later, the CPU and memories are released from reset to allow the reset vector sequence to occur.
The SIM actively pulls down the (RST) pin for all internal reset sources.
13.5 SIM Counter
The SIM counter is used by the power-on reset module (POR) and in stop mode recovery to allow the
oscillator time to stabilize before enabling the internal bus (IBUS) clocks. The SIM counter also serves as
a prescaler for the computer operating properly module (COP). The SIM counter uses 12 stages for
counting, followed by a 13th stage that triggers a reset of SIM counters and supplies the clock for the COP
module. The SIM counter is clocked by the falling edge of BUSCLKX4.
13.5.1 SIM Counter During Power-On Reset
The power-on reset module (POR) detects power applied to the MCU. At power-on, the POR circuit
asserts the signal PORRST. Once the SIM is initialized, it enables the oscillator to drive the bus clock
state machine.
13.5.2 SIM Counter During Stop Mode Recovery
The SIM counter also is used for stop mode recovery. The STOP instruction clears the SIM counter. After
an interrupt, break, or reset, the SIM senses the state of the short stop recovery bit, SSREC, in the
configuration register 1 (CONFIG1). If the SSREC bit is a 1, then the stop recovery is reduced from the
normal delay of 4096 BUSCLKX4 cycles down to 32 BUSCLKX4 cycles. This is ideal for applications
using canned oscillators that do not require long start-up times from stop mode. External crystal
applications should use the full stop recovery time, that is, with SSREC cleared in the configuration
register 1 (CONFIG1).
13.5.3 SIM Counter and Reset States
External reset has no effect on the SIM counter (see
free-running after all reset states. See
internal reset recovery sequences.
13.6 Exception Control
Normal sequential program execution can be changed in three different ways:
13.6.1 Interrupts
An interrupt temporarily changes the sequence of program execution to respond to a particular event.
Figure 13-7
Freescale Semiconductor
1. Interrupts
2. Reset
3. Break interrupts
a. Maskable hardware CPU interrupts
b. Non-maskable software interrupt instruction (SWI)
flow charts the handling of system interrupts.
MC68HC908QL4 Data Sheet, Rev. 8
13.4.2 Active Resets from Internal Sources
13.7.2 Stop Mode
DD
rises above V
for details.) The SIM counter is
TRIPR
. Sixty-four BUSCLKX4
for counter control and
SIM Counter
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