DS508UM1
35
2.12
Serial Interfaces
In addition to the two UARTs, the EP7312 offers the following serial interfaces shown in Table 17. The
inputs / outputs of three of the serial interfaces (DAI, CODEC, and SSI2) are multiplexed onto a single set
of external interface pins. If the DAISEL bit of SYSCON3 is low, then either SSI2 or the CODEC interface
will be selected to connect to the external pins. When bit 0 of SYSCON2 (SERSEL) is high, then the CO-
DEC is connected to the external pins, when low the master / slave SSI2 is connected to these pins. When
the DAISEL bit is set high, the DAI interface is connected to the external pins. On power up, both the DA-
ISEL and SERSEL bits are reset low, thus the master / slave SSI2 will be connected to these pins (and con-
figured for slave mode operation to avoid external drive clashes).
The unique internal names given in Table 17 to each of the serial interfaces will be used to describe each
interface.
Pin definition information for the three multiplexed serial interfaces (SSI2, DAI, and CODEC) and the
ADC interface is described in Table 18.
Type
Comments
Referred To As
Max. Transfer Speed
SPI / Microwire 1
Master mode only
ADC Interface
128 kbits/s
SPI / Microwire 2
Master / slave mode
SSI2 Interface
512 kbits/s
DAI Interface
CD quality DACs and ADCs
DAI Interface
1.536 Mbits/s
CODEC Interface
Only for use in the PLL clock mode
CODEC
Interface
64 kbits/s
Table 17. Serial Interface Options
Pin
No.
LQFP
External
Pin Name
SSI2
Slave Mode
(Internal Name)
SSI2
Master
Mode
CODEC
Internal Name
DAI
Internal Name
Strength
63
SSICLK
SSICLK = serial
bit clock; Input
Output
PCMCLK =
Output
SCLK =
Output
1
65
SSITXFR
SSKTXFR = TX
frame sync; Input
Output
PCMSYNC = Output
LRCK = Output
1
66
SSITXDA
SSITXDA = TX
data; Output
Output
PCMOUT = Output
SDOUT = Out-
put
1
67
SSIRXDA
SSIRXDA = RX
data; Input
Input
PCMIN = Input
SDIN = Input
68
SSIRXFR
SSIRXFR = RX
frame sync; Input
Output
p/u
(use a 10k pull-up)
MCLK
1
Table 18. Serial Pin Assignments
Summary of Contents for EP7312
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