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Advanced Technology Attachment (ATA)
23-12
Freescale Semiconductor
23.3.6.3
Interrupt Clear Register (ATA_ICR)
The interrupt clear register clears the FIFO underflow/overflow status bits in the ATA_ISR register.
23.3.7
FIFO Alarm Register (FIFO_ALARM)
The FIFO alarm register contains threshold to generate the FIFO transmit and receive requests to the DMA
controller:
•
If (ATA_CR[FREFILL] == 1 and and FIFO_FILL < FIFO_ALARM)
then request is sent to the DMA controller to refill the FIFO.
•
If (ATA_CR[FEMPTY] == 1 and and FIFO_FILL
FIFO_ALARM)
then request is sent to the DMA controller to empty the FIFO.
23.3.8
Drive Registers
Some drive registers are addressable, but are not present in ATA interface module.
list of these registers. If a read or write access is made to one of these registers, read or write maps to a PIO
read or write cycle on the ATA bus, and the corresponding register in the device attached to the ATA bus
Address: 0x9000_0030 (ATA_ICR)
Access: User write-only
7
6
5
4
3
2
1
0
R
W
FUF
FOF
Reset
—
—
—
—
—
—
—
—
Figure 23-9. ATA_ICR Register
Table 23-7. ATA_ICR Field Description
Field
Description
7
Reserved.
6
FUF
FIFO underfow clear. Writing a 1 to this bit clears the corresponding bit in the ATA_ISR. Writing a 0 has no effect.
5
FOF
FIFO overflow clear. Writing a 1 to this bit clears the corresponding bit in the ATA_ISR. Writing a 0 has no effect.
4–0
Reserved.
Address: 0x9000_0034 (FIFO_ALARM)
Access: User read/write
7
6
5
4
3
2
1
0
R
FIFO_ALARM
W
Reset
0
0
0
0
0
0
0
0
Figure 23-10. FIFO_Alarm Register
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 ...