User Manual

EP7309/11/12 User’s Manual - DS508UM4 16-3
Copyright Cirrus Logic, Inc. 2003
DAI/CODEC/SSI2
1616
16
ldr r1, =DAISEL
str r1, [r12, #0x100] ; Select DAI in SYSCON1 0x8000.0100
ldr r1, =DAI64FS
add r11,r11,#0x1000 ; Set 0x8000.2000 base address
str r1, [r11, #0x600] ; Set DAI64FS 0x8000.2600
ldr r1, [r11, #0x200]
mov r0, #1
bic r1, r1, r0, lsl #9 ; Clear bit 9 in SYSCON3 for 64fs
str r1, [r11, #0x200] ; Set 64fs mode in SYSCON3 0x8000.2000
ldr r1, =DAIEN
str r1, [r11, #0x0] ; Enable DAI at 0x8000.2000
ldr r1, =DAISTATUS
str r1, [r11, #0x100] ; Clear Status Register
;
Operational Overview
DAI/CODEC/SSI2 MUX
The DAI, CODEC, and the SSI 2 interfaces share the same set of ex ternal pins on th e
EP73xx. In addition to enabling only one of these interfaces, a M UX must be
programmed to select the interface to be used with the SSI pins. Figure 16-1 on
page 16-2 illustratesthisMUX.Table 16-2 is a matrix detailing the minimum set of
configuration bits that must be programmed to properly use one of these interfaces.
(H) = High (Set)
(X) = Don’t care
To p rogram the MU X , you will need to do the following: To conn ect the port to any of
the 4 features shown a bove, a minimum software configuration shown in the table
abovemustbeobserved.Eachregistercolumncontainsthebitname(bit#)thatmust
be c leared or set for each feature as shown in the column. This tab le does not
complete the programming for each of the f eatures, but allows access to the port only.
The interrupt masks for these features will have to be program med as well.
Table 16-2: Matrix for Programming the MUX
FEATURE SYSCON2 SYSCON3 DAI64 Fs DAIR(DAI)
DAI –128Fs (X) DAISEL[3] (H) I2SF64[0] (L) DAIEN[16] (H)
128Fs[9] (H)
DAI-64Fs (X) DAISEL[3] (H) I2SF64[0] (H) DAIEN[16] (H)
128Fs[9] (L)
SSI2 SERSEL[0] (L) (X) (X) DAIEN[16] (L)
CODEC SERSEL[0] (H) (X) (X) DAIEN[16] (L)