MCIMX351AVM4B Freescale, MCIMX351AVM4B Datasheet - Page 101

• Manufacturer Part Number: MCIMX351AVM4B
• Manufacturer: Freescale

Specifications of MCIMX351AVM4B

• Operating Temperature (min): -40C
• Operating Temperature (max): 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Compliant

1
4.9.17
The parallel ATA module can work on PIO/multiword DMA/ultra-DMA transfer modes (not available for
the MCIMX351). Each transfer mode has a different data transfer rate, Ultra DMA mode 4 data transfer
rate is up to 100 MBps.
The parallel ATA module interface consists of a total of 29 pins. Some pins have different functions in
different transfer modes. There are various requirements for timing relationships among the function pins,
in compliance with the ATA/ATAPI-6 specification, and these requirements are configurable by the ATA
module registers.
4.9.17.1
Table 64
4.9.17.2
This section discusses ATA parameters. For a detailed description, refer to the ATA-6 specification.
Level shifters are required for 3.3-V or 5.0-V compatibility on the ATA interface.
The use of bus buffers introduces delays on the bus and introduces skew between signal lines. These
factors make it difficult to operate the bus at the highest speed (UDMA-5) when bus buffers are used. Use
of bus buffers is not recommended if fast UDMA mode is required.
The ATA specification imposes a slew rate limit on the ATA bus. According to this limit, any signal driven
on the bus should have a slew rate between 0.4 and 1.2 V/ns with a 40 pF load. Few vendors of bus buffers
specify the slew rate of the outgoing signals.
When bus buffers are used the ata_data bus buffer is bidirectional, and uses the direction control signal
ata_buffer_en. When ata_buffer_en is asserted, the bus should drive from host to device. When
Freescale Semiconductor
SI1
SI2
SI3
ID
SRISE and SFALL meet this requirement when measured at the sender’s connector from 10–90% of full signal amplitude with
all capacitive loads from 15 pF through 40 pF, where all signals have the same capacitive load value.
ATA Interface Signals
Rising edge slew rate for any signal on the ATA interface
Falling edge slew rate for any signal on the ATA interface
Host interface signal capacitance at the host connector
and
Parallel ATA Module AC Electrical Specifications
General Timing Requirements
Figure 75
ATA Electrical Specifications (ATA Bus, Bus Buffers)
define the AC characteristics of the interface signals on all data transfer modes.
i.MX35 Applications Processors for Automotive Products, Rev. 9
Table 64. AC Characteristics of All Interface Signals
Figure 75. ATA Interface Signals Timing Diagram
Parameter
SI2
1
1
SI1
Symbol
S
C
S
rise
fall
host
1
1
Min.
—
—
—
Max.
1.25
1.25
20
Unit
V/ns
V/ns
pF
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