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Advanced Technology Attachment (ATA)
Freescale Semiconductor
23-9
23.3.6
Interrupt Registers
A group of three registers controls the interrupt interface from the ATA module to the CPU’s interrupt
controller and DMA controller.
•
Interrupt request. Bits 3–6 of the interrupt registers control ATA interrupts. A request to the
interrupt controller generates if one of the four bits is set in the interrupt status register (ATA_ISR),
while the same bit is set in the interrupt enable register (ATA_IER).
Address: 0x9000_0024 (ATA_CR)
Access: User read/write
7
6
5
4
3
2
1
0
R
FEN
RESET
FREFILL
FEMPTY
DMAPEND
DMAMODE
DMADIR
IORDYEN
W
Reset
0
0
0
0
0
0
0
0
Figure 23-6. ATA Control Register (ATA_CR)
Table 23-4. ATA_CR Field Descriptions
Field
Description
7
FEN
This field controls if the internal FIFO is in reset or enabled
0 FIFO reset
1 FIFO normal operation
6
RESET
Controls the level on the ATA_RESET pin, and controls the reset of the internal ATA protocol engine.
0 ATA_RESET = 0, ATA drive is reset, and internal protocol engine reset.
1 ATA_RESET = 1, ATA drive is not reset, and internal protocol engine normal operation.
5
FREFILL
FIFO transmit enable. Controls if the FIFO makes transmit data requests to the DMA. If enabled, the FIFO
requests the DMA to refill it when FIFO filling drops below the alarm level.
0 FIFO refill by DMA disabled
1 FIFO refill by DMA enabled
4
FEMPTY
FIFO receive enable. Controls if the FIFO makes receive data requests to the DMA. If enabled, the FIFO
requests the DMA to empty it whenr FIFO filling becomes greater or equal to the alarm level.
0 FIFO empty by DMA disabled
1 FIFO empty by DMA enabled
3
DMAPEND
DMA pending bit. This bit controls if the ATA interface responds to a DMA request originating in the drive.
If this bit asserts, the ATA interface starts a multiword DMA or ultra DMA burst when the drive asserts
ATA_DMARQ.
0 ATA interface does not start DMA burst
1 ATA interface starts multiword DMA or ultra DMA burst when drive asserts ATA_DMARQ
2
DMAMODE
DMA mode. If a DMA burst starts, the UDMA or MDMA protocol is used.
0 Multiword DMA protocol is used
1 Ultra DMA protocol is used
1
DMADIR
DMA burst direction. Indicates the data direction on any DMA burst started.
0 DMA in burst, ATA interface reads from drive
1 DMA out burst, ATA interface writes to drive
0
IORDYEN
IORDY enable. Indicates if the ATA_IORDY handshake is used during PIO mode.
0 IORDY is disregarded
1 IORDY handshake is used
Summary of Contents for MCF54455
Page 33: ...xxviii Freescale Semiconductor ...
Page 67: ...Freescale Semiconductor 1 ...
Page 125: ...Freescale Semiconductor 1 ...
Page 145: ...Enhanced Multiply Accumulate Unit EMAC 5 21 Freescale Semiconductor ...
Page 173: ...Cache 6 28 Freescale Semiconductor ...
Page 179: ...Static RAM SRAM 7 6 Freescale Semiconductor ...
Page 207: ...Power Management 9 16 Freescale Semiconductor ...
Page 323: ...Reset Controller Module 13 8 Freescale Semiconductor ...
Page 389: ...Pin Multiplexing and Control 16 44 Freescale Semiconductor ...
Page 575: ...PCI Bus Controller 22 58 Freescale Semiconductor ...
Page 600: ...Advanced Technology Attachment ATA Freescale Semiconductor 23 25 ...
Page 601: ...Freescale Semiconductor 1 ...
Page 842: ...I2 C Interface Freescale Semiconductor 33 16 ...
Page 843: ...Freescale Semiconductor 1 ...
Page 921: ...Revision History A 6 Freescale Semiconductor ...