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14 modem-out status register (mosr), 15 modem-in status register (misr), Table 13-20 – Intel PXA255 User Manual

Page 482

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13-30

Intel® PXA255 Processor Developer’s Manual

AC’97 Controller Unit

13.8.3.14

Modem-Out Status Register (MOSR)

This is a read/write register. Ignore reads from reserved bits. Write zeros to reserved bits.

13.8.3.15

Modem-In Status Register (MISR)

This is a read/write register. Ignore reads from reserved bits. Write zeros to reserved bits.

Table 13-19. MICR Bit Definitions

Physical Address

4050_0108

MICR Register

AC’97 Controller Unit

Bit

31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9

8

7

6

5

4

3

2

1

0

reserved

FEIE

re

se

rv

e

d

Reset 0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Bits

Name

Description

31:4

reserved

3

FEIE

FIFO Error Interrupt Enable (FEIE)
Controls whether a receive FIFO error causes an interrupt.
0 = No interrupt will occur even if bit 4 in the MISR is set

1 = An interrupt will occur if bit 4 in the MISR is set.

2:0

reserved

Table 13-20. MOSR Bit Definitions

Physical Address

4050_0110

MOSR Register

AC’97 Controller Unit

Bit

31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9

8

7

6

5

4

3

2

1

0

reserved

FIFO

E

re

s

erv

e

d

Reset 0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Bits

Name

Description

31:5

reserved

4

FIFOE

FIFO error (FIFOE)
0 = No transmit FIFO errors have occurred
1 = A transmit FIFO error occurred. This bit is set if a transmit FIFO underrun occurs. In

this case, the last valid sample is repetitively sent out and the pointers are not
incremented.This could happen due to:

c. No more valid buffer data available for transmits.
d. Buffer data available but DMA controller has excessive bandwidth requirements.

Bit is cleared by writing a 1 to this bit position.

3:0

reserved