MC68EC040RC25 Freescale Semiconductor, MC68EC040RC25 Datasheet - Page 227

• Manufacturer Part Number: MC68EC040RC25
• Manufacturer: Freescale Semiconductor

Specifications of MC68EC040RC25

• Family Name: M68000
• Device Core: ColdFire
• Device Core Size: 32b
• Frequency (max): 25MHz
• Instruction Set Architecture: RISC
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Mounting: Through Hole
• Pin Count: 179
• Package Type: PGA
• Lead Free Status / Rohs Status: Supplier Unconfirmed

Note that a mask value of 6 and a mask value of 7 both inhibit request levels of 1–6 from
being recognized. In addition, neither masks a transition to an interrupt request level of 7.
The only difference between mask values of 6 and 7 occurs when the interrupt request
level is 7 and the mask value is 7. If the mask value is lowered to 6, a second level 7
interrupt is recognized.
External circuitry can chain or otherwise merge signals from devices at each level,
allowing an unlimited number of devices to interrupt the processor. When several devices
are connected to the same interrupt level, each device should hold its interrupt priority
level constant until its corresponding interrupt acknowledge bus cycle ensures that all
requests are processed. Refer to Section 7 Bus Operation for details on the interrupt
acknowledge cycle.
8-14
IF
IF
IF
IF STILL
IF
IF
IF
IF STILL
100 ($3)
EXTERNAL
001 ($6)
000 ($7)
100 ($3)
IPL2–IPL0
001 ($6)
001 ($6)
100 ($3)
100 ($3)
000 ($7)
000 ($7)
Figure 8-3. Interrupt Recognition Examples
Freescale Semiconductor, Inc.
AND RTE SO THAT
AND RTE SO THAT
For More Information On This Product,
AND STILL
AND STILL
THEN
THEN
AND STILL
AND STILL
M68040 USER’S MANUAL
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INTERRUPT PRIORITY
110 ($6)
111 ($7)
MASK (I2–I0)
110 ($6)
111 ($7)
101 ($5)
110 ($6)
101 ($5)
101 ($5)
111 ($7)
101 ($5)
AND
AND
THEN
THEN
THEN
THEN
THEN
THEN
LEVEL 6 INTERRUPT
LEVEL 7 INTERRUPT
NO ACTION
NO ACTION
NO ACTION
LEVEL 6 INTERRUPT
NO ACTION
LEVEL 7 INTERRUPT (LEVEL COMPARISON)
ACTION
(INITIAL CONDITIONS)
(INITIAL CONDITIONS)
(LEVEL COMPARISON)
(LEVEL COMPARISON)
(TRANSITION)
(TRANSITION)
MOTOROLA