ST18D952 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
'ST18D952' PDF : 67 Pages View PDF
ST18952
SSR: SIO Status register
(SIO0 address = 0065h, reset value = 0000 h, read only)
(SIO1 address = 00E5h, reset value = 0000 h, read only)
15 14 13 12 11 10 9 8 7 6 5
SLRA(7:0)
SCWN(2:0)
43210
0 SROV SRDF STUN STDE
Bit
STDE
STUN
SRDF
SROV
Bit 4
SCWN(2:0)
SLRA(7:0)
Function
SIO Transmit data empty
• STDE is set when the content of the STDR Data register is transferred into the Trans-
mit Shift register signalling that the STDR Data register is ready to be receive the next
word to be transmitted.
• If the STIE enable bit is set, an interrupt request occurs on the STI output (STI is low
for 1 MCLK cycle) when STDE is set.
SIO Transmit underrun
• STUN is set when the Transmit Shift register is empty and the STDR Data register
has not been filled by the DSP.
• If another frame syncho occurs, the content of the STDR Data register is transferred
again into the Transmit Shift register and the previous word is re-transmitted.
SIO Receive data full
• SRDF is set when the content of the Receive Shift register has been transferred into
the SRDR Data register, signalling a new word receive. The SRDR Data register is
ready to be read by the DSP.
• If the SRIE enable bit is set, an interrupt request occurs on the SRI output (SRI is low
for 1 MCLK cycle) when SRDF is set.
SIO Receive overrun
• SROV is set when the Receive Shift register is ready to be transferred into the SRDR
Data register, which has not been read by the DSP.
• If another frame syncho occurs, the content of the Receive Shift register is transferred
into the SRDR Data register and the previous content of SRDR is lost.
Unused and read as ‘0’
SIO Current word number (SCWN(2) = msb)
• In normal and microwire modes, SCWN contains the current word number value
since the last frame synchro. In tdm mode, SCWN determines the current slot number
value since the last frame synchro.
SCWN = 0 -> 1st sub-frame / time slot
SCWN = 1 -> 2nd sub-frame / time slot
...
SCWN = 7 -> 8th sub-frame / time slot
SIO Last received address (bits 15-8)
Must write 0.
40/66
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