MC68020RC20E Freescale Semiconductor, MC68020RC20E Datasheet - Page 122

• Manufacturer Part Number: MC68020RC20E
• Description: IC MICROPROCESSOR 32BIT 114-PGA
• Manufacturer: Freescale Semiconductor

Specifications of MC68020RC20E

• Processor Type: M680x0 32-Bit
• Speed: 20MHz
• Voltage: 5V
• Mounting Type: Surface Mount
• Package / Case: 114-PGA
• Family Name: M68000
• Device Core: ColdFire
• Device Core Size: 32b
• Frequency (max): 20MHz
• Instruction Set Architecture: RISC
• Supply Voltage 1 (typ): 5V
• Operating Supply Voltage (max): 5.25V
• Operating Supply Voltage (min): 4.75V
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Mounting: Through Hole
• Pin Count: 114
• Package Type: PGA
• Lead Free Status / RoHS Status: Contains lead / RoHS Compliant
• Features: -
• Lead Free Status / Rohs Status: Compliant

The existing three-wire arbitration design (BR, BG, and BGACK) of some peripherals can
be converted to the MC68EC020 two-wire arbitration with the addition of an AND gate.
Figure 5-50 shows the combination of BR and BGACK for a three-wire arbitration system
to BR of the MC68EC020 or BR and BG from an MC68EC020 to BG for a three-wire
arbitration system. The speed of the AND gate must be faster than the time between the
assertion of BGACK and the negation of BR by the alternate bus master. Figure 5-50
assumes the alternate bus master does not assume bus mastership until the MC68EC020
AS is negated and MC68EC020 BG is asserted.
MOTOROLA
SIZ1–SIZ0
FC2–FC0
DSACK1
DSACK0
D31–D0
A23–A0
Figure 5-49. MC68EC020 Bus Arbitration Operation Timing—Bus Inactive
CLK
R/W
AS
DS
BR
BG
PROCESSOR
S4
Freescale Semiconductor, Inc.
(ARBITRATION PERMITTED
WHILE THE PROCESSOR IS
For More Information On This Product,
INACTIVE OR HALTED)
BUS INACTIVE
Go to: www.freescale.com
M68020 USER’S MANUAL
ALTERNATE MASTER
S0
PROCESSOR
5- 75