MC68376BGMAB20 Freescale Semiconductor, MC68376BGMAB20 Datasheet - Page 101

• Manufacturer Part Number: MC68376BGMAB20
• Description: IC MCU 32BIT 8K ROM 160-QFP
• Manufacturer: Freescale Semiconductor
• Series: M683xxr

Specifications of MC68376BGMAB20

• Core Processor: CPU32
• Core Size: 32-Bit
• Speed: 20MHz
• Connectivity: CAN, EBI/EMI, SCI, SPI
• Peripherals: POR, PWM, WDT
• Number Of I /o: 18
• Program Memory Type: ROMless
• Ram Size: 7.5K x 8
• Voltage - Supply (vcc/vdd): 4.75 V ~ 5.25 V
• Data Converters: A/D 16x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 160-QFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Program Memory Size: -

5.5.1.8 Data and Size Acknowledge Signals
5.5.1.9 Bus Error Signal
5.5.1.10 Halt Signal
MC68336/376
USER’S MANUAL
The supervisor bit in the status register determines whether the CPU is operating in
supervisor or user mode. Addressing mode and the instruction being executed deter-
mine whether a memory access is to program or data space.
During normal bus transfers, external devices assert the data and size acknowledge
signals (DSACK[1:0]) to indicate port width to the MCU. During a read cycle, these sig-
nals tell the MCU to terminate the bus cycle and to latch data. During a write cycle, the
signals indicate that an external device has successfully stored data and that the cycle
can terminate. DSACK[1:0] can also be supplied internally by chip-select logic. Refer
to 5.9 Chip-Selects for more information.
The bus error signal (BERR) is asserted when a bus cycle is not properly terminated
by DSACK or AVEC assertion. It can also be asserted in conjunction with DSACK to
indicate a bus error condition, provided it meets the appropriate timing requirements.
Refer to 5.6.5 Bus Exception Control Cycles for more information.
The internal bus monitor can generate the BERR signal for internal-to-internal and
internal-to-external transfers. In systems with an external bus master, the SIM bus
monitor must be disabled and external logic must be provided to drive the BERR pin,
because the internal BERR monitor has no information about transfers initiated by an
external bus master. Refer to 5.6.6 External Bus Arbitration for more information.
The halt signal (HALT) can be asserted by an external device for debugging purposes
to cause single bus cycle operation or (in combination with BERR) a retry of a bus cy-
cle in error. The HALT signal affects external bus cycles only. As a result, a program
not requiring use of the external bus may continue executing, unaffected by the HALT
signal.
FC2
0
0
0
0
1
1
1
1
Table 5-10 Address Space Encoding
SYSTEM INTEGRATION MODULE
FC1
0
0
1
1
0
0
1
1
FC0
0
1
0
1
0
1
0
1
Supervisor program space
Supervisor data space
User program space
User data space
Address Space
CPU space
Reserved
Reserved
Reserved
MOTOROLA
5-23