MCF5272VF66 Freescale, MCF5272VF66 Datasheet - Page 288

• Manufacturer Part Number: MCF5272VF66
• Manufacturer: Freescale

Specifications of MCF5272VF66

• Family Name: MCF5xxx
• Device Core: ColdFire
• Device Core Size: 32b
• Frequency (max): 66MHz
• Instruction Set Architecture: RISC
• Supply Voltage 1 (typ): 3.3V
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 196
• Package Type: MA-BGA
• Lead Free Status / RoHS Status: Not Compliant

Universal Serial Bus (USB)
12.3.4
The access times for the USB module depend on whether the access is to a register, to an endpoint FIFO
(EPnDR register), or to the configuration RAM.
12.3.4.1
The USB module registers are accessed through the internal S-bus. Each register access takes 3 clock
cycles for reads and writes.
12.3.4.2
The FIFO access time depends on the size, the time between accesses, and whether the previous FIFO
access was for the same endpoint. After a longword access to an endpoint’s FIFO, the next longword in
the FIFO is cached for a quicker access time on the next longword read. This mechanism is reset every
time another endpoint is accessed.
12.3.4.3
The configuration RAM is longword accessible only. Access times for reads from the configuration RAM
are eight clock cycles per access. Clock cycle access times for back-to-back writes to the configuration
RAM are 3-5-5-5-5-5... Access times for writes separated by at least 1 clock cycle are 3-3-3-3-3-3…
12-30
9. Interface #0 Descriptor
10. Endpoint #1 Descriptor
11. Configuration #3 Descriptor
12. Interface #0 Descriptor
13. Endpoint #1 Descriptor
14. Endpoint #2 Descriptor
USB Module Access Times
Registers
Endpoint FIFOs
Configuration RAM
Byte
Word
Long (back to back)
Long (1 clock gap)
Long (2 clock gap)
Long (3+ clock gap)
MCF5272 ColdFire
Access Type
Table 12-19. USB FIFO Access Timing
Table 12-19
®
Integrated Microprocessor User’s Manual, Rev. 3
5
6
8-4-6-6-6-6...
8-3-5-5-5-5...
8-3-4-4-4-4...
8-3-3-3-3-3...
shows the access times for the FIFOs.
Read
4
4
4-6-6-6-6-6...
4-5-5-5-5-5...
4-4-4-4-4-4...
4-4-4-4-4-4...
Write
Freescale Semiconductor