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
reserved
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
3FEIE
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
FIFOE
reserved
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
4FIFOE
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