Intel PXA255 Speaker System User Manual


 
Intel® PXA255 Processor Developer’s Manual 14-11
Inter-Integrated-Circuit Sound (I2S) Controller
14.6.3 Serial Audio Controller I
2
S/MSB-Justified Status Register
(SASR0)
SASR0, shown in Table 14-7, is used for recording the status of the FIFOs and I2SLINK.
Only 4 bits are assigned for TFL and RFL. Actual fill levels are interpreted as follows:
Actual_TFL(4:0) = {~TNF, TFL(3:0)}
Actual_RFL(4:0) calculation:
if (RFL(3:0) == 4’b0)
Actual_RFL(4:0) = {RNE, RFL(3:0)}
else
Actual_RFL(4:0) = {1’b0, RFL(3:0)}
This is a read-only register. Ignore reads from reserved bits.
Table 14-6. SACR1 Bit Definitions
Physical Address
0x4040_0004
Serial Audio Controller I
2
S/MSB-
Justified Control Register
I
2
S Controller
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
ENLBF
DRPL
DREC
reserved
AMSL
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
31:6 reserved
5ENLBF
Enable I
2
S/MSB Interface Loop Back Function:
0 = I
2
S/MSB Interface Loop Back Function is disabled
1 = I
2
S/MSB Interface Loop Back Function is enabled
4DRPL
Disable Replaying Function of I
2
S or MSB-Justified Interface:
0 = Replaying Function is enabled
1 = Replaying Function is disabled
3DREC
Disable Recording Function of I
2
S or MSB-Justified Interface:
0 = Recording Function is enabled
1 = Recording Function is disabled
2:1 reserved
0AMSL
Specify Alternate Mode (I
2
S or MSB-Justified) Operation:
0 = Select I
2
S Operation Mode
1 = Select MSB-Justified Operation Mode