Table 30-8 I2S Mode Selection - Motorola DragonBall MC9328MX1 Reference Manual

Table 30-7. SSI Control/Status Register Description (Continued)
Name
TFE Transmit FIFO Empty—Indicates that the data level in the
Bit 0 transmit FIFO reaches the Transmit FIFO Empty Water Mark.
The Water Mark is defined in the TFWM field of the SSI FIFO
Control/Status Register (SFCSR). The transmit FIFO must be
enabled or TFE is meaningless.
When TFE is set, data can be written to the transmit FIFO via the
STX register.
Note: An interrupt is generated only when both the TFE and
TIE (of the STCR) are set and the transmit FIFO is enabled (the
TFEN bit in the STCR is set).
2
30.3.7.1 I S Mode Selection
The SCSR contains two bits, the I
mode of the SSI module. This section explains how the mode of the module affects the bits in the other SSI
registers. Table 30-8 summarizes the mode settings.
In normal mode operation, no register bits are forced to any particular state internally and the SSI can be
programmed to work in any operating condition.
2
When entering I S modes (I
to write to these bits when in I
Table 30-9.
The user must configure the bit clock in the STCCR and the SRCCR.
2
I S Mode
Master or save
Master or save
Master or save
Master or save
Master or save
MOTOROLA
Description
2
S Mode Select (I2S MODE1 and I2S MODE0) bits, that determine the
Table 30-8. I
I2S_MODE [1] I2S_MODE [0]
0
0
1
1
2 2
S master or I S slave), several control bits are fixed in the hardware. Attempts
2 2
S master or I S slave mode are ignored. These bits are described in
2
Table 30-9. I S Master or I
Bit Register Forced
Name Location Value
SYN SCSR [12]
NET SCSR [11]
TSHFD STCR [4]
RSHFD SRCR [4]
TSCKP STCR [3]
Synchronous Serial Interface (SSI)
2
S Mode Selection
Remark
0 Normal mode
1 2
I S master mode
0 2
I S slave mode
1 Normal mode
2
S Slave Mode Settings
Function
1 Synchronous mode enabled
1 Network mode enabled
0 Transmission direction is MSB first
0 Receive direction is MSB first
1 Falling edge of bit clock clocks data out
Programming Model
Settings
0 = Data level in the transmit
FIFO exceeds Water
Mark
1 = Data level in the transmit
FIFO below Watermark
30-19