EP9312-IB Cirrus Logic Inc, EP9312-IB Datasheet - Page 777

• Manufacturer Part Number: EP9312-IB
• Description: IC ARM920T MCU 200MHZ 352-PBGA
• Manufacturer: Cirrus Logic Inc
• Series: EP9r

Specifications of EP9312-IB

• Core Processor: ARM9
• Core Size: 16/32-Bit
• Speed: 200MHz
• Connectivity: EBI/EMI, EIDE, Ethernet, I²C, IrDA, Keypad/Touchscreen, SPI, UART/USART, USB
• Peripherals: AC'97, DMA, I&sup2:S, LCD, LED, MaverickKey, POR, PWM, WDT
• Number Of I /o: 16
• Program Memory Type: ROMless
• Ram Size: 32K x 8
• Voltage - Supply (vcc/vdd): 1.65 V ~ 3.6 V
• Data Converters: A/D 8x12b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 352-BGA
• Processor Series: EP93xx
• Core: ARM920T
• Data Bus Width: 32 bit
• 3rd Party Development Tools: MDK-ARM, RL-ARM, ULINK2
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Program Memory Size: -
• Lead Free Status / Rohs Status: No
• Other names: 598-1259

DS785UM1
27.2.7 DMA Request Latency
27.2.7.1 DMA Request Deassertion
27.2.7.2 DMA Request Latency Overview
latching of the data. It is calculated that the cycle time of AHB clock has to be smaller than
(IDE cycle time)*2/3. For different UDMA speed modes, the minimum AHB clock speeds are
listed below. There is no special speed constraint imposed on the design for PIO and MDMA
modes.
Multi-word DMA Write to IDE Controller:
The DMAide signal deassertion is generated based on the AHB write logic. The act of writing
to the Multi-word DMA write-FIFO causes the deassertion to appear on the following bus
cycle.
Multi-word DMA Read from IDE Controller:
The DMAide signal deassertion is generated based on the AHB read logic. The act of
reading from the Multi-word DMA read-FIFO causes the deassertion to appear on the
following bus cycle.
Ultra DMA Write to IDE Controller:
The DMAide signal deassertion is generated based on the contents of the Ultra DMA write
FIFO. If the FIFO contains four or more elements, the DMAide signal deasserts.
Ultra DMA Read from IDE Controller:
The DMAide signal deassertion is generated based on an internal counter. The DMAide
signal will deassert if four DMA reads have occurred or if the FIFO is now empty (which only
occurs at the end of a non-quad word aligned read from the IDE device)
The IDE controller requires a certain number of cycles to deassert the DMA request line
DMAide after a DMA access for Multi-word DMA and Ultra DMA modes. The number of wait-
states required are listed below in addition to the pipeline breakdown of the signal
propagation. The assumption is that the deassertion should follow an AHB bus command
(read or write) in HCLK cycle 1.
UDMA Speed Mode
0
1
2
3
4
Table 27-2. IDE Cycle Times and Data Transfer Rates
Min. IDE Cycle Time
Copyright 2007 Cirrus Logic
112 ns
73 ns
54 ns
39 ns
25 ns
Max. AHB Cycle
74.7 ns
48.7 ns
36.0 ns
26.0 ns
16.7 ns
Time
Min. AHB Clock
Frequency
13.4 MHz
20.5 MHz
27.8 MHz
38.5 MHz
59.8 MHz
EP93xx User’s Guide
IDE Interface
27-7
27