MC68HC000FN16 Freescale Semiconductor, MC68HC000FN16 Datasheet - Page 70

• Manufacturer Part Number: MC68HC000FN16
• Description: IC MPU 32BIT 16MHZ 68-PLCC
• Manufacturer: Freescale Semiconductor

Specifications of MC68HC000FN16

• Processor Type: M680x0 32-Bit
• Speed: 16MHz
• Voltage: 3.3V, 5V
• Mounting Type: Surface Mount
• Package / Case: 68-PLCC
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Features: -

The MC68010 also differs from the other microprocessors described in this manual
regarding bus errors. The MC68010 can detect a late bus error signal asserted within one
clock cycle after the assertion of data transfer acknowledge. When receiving a bus error
signal, the processor can either initiate a bus error exception sequence or try running the
cycle again.
5.4.1 Bus Error Operation
In all the microprocessors described in this manual, a bus error is recognized when
DTACK and HALT are negated and BERR is asserted. In the MC68010, a late bus error is
also recognized when HALT is negated, and DTACK and BERR are asserted within one
clock cycle.
When the bus error condition is recognized, the current bus cycle is terminated in S9 for a
read cycle, a write cycle, or the read portion of a read-modify-write cycle. For the write
portion of a read-modify-write cycle, the current bus cycle is terminated in S21. As long as
BERR remains asserted, the data and address buses are in the high-impedance state.
Figure 5-25 shows the timing for the normal bus error, and Figure 5-26 shows the timing
for the MC68010 late bus error.
5-24
FC2–FC0
LDS/UDS
D15–D0
A23–A1
DTACK
BERR
HALT
R/W
CLK
AS
S0
INITIATE
READ
M68000 8-/16-/32-BIT MICROPROCESSORS USER'S MANUAL
S2
Figure 5-25. Bus Error Timing Diagram
Freescale Semiconductor, Inc.
S4
For More Information On This Product,
RESPONSE
FAILURE
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Go to: www.freescale.com
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S6
BUS ERROR
DETECTION
S8
ERROR STACKING
INITIATE BUS
MOTOROLA