MPEG Packet Data Output MT312
When ERR IND is High: BKERR remains high when error free MPEG packets are being output on the
MDO[7:0] bus. BKERR goes low when there is no De-scrambler lock OR on the first
byte of a packet where uncorrectable bytes are detected. BKERR remains low until
error free MPEG packets are being output on the MDO[7:0] bus.
When ERR IND is Low: BKERR remains high when error free MPEG packets are being output on the
MDO[7:0] bus. BKERR goes low on the first byte of a packet where uncorrectable
bytes are detected and will remain low until the 188th byte (DVB) or 130th byte
(DSS) has been clocked out.
Note: the signal on pin 75 can be inverted by setting the BKERIV bit 6 of OP CTRL register 96, see 48.
1st byte packet n
MCLKIV=1
188 (DVB) or 130 (DSS) byte packet n
1st byte packet n+1
MOCLK
MDO7:0
MOSTRT
MOVAL
DS lock
ERR_IND = 0
BKERR
ERR_IND = 1
BKERR
Ti
Tp
Figure 24 - MT312 output data wave form diagram 2
Figure 23 illustrates the case when ERR IND is set high and the De-scrambler lock is lost during output of the
first packet. The first packet shown is good, in which case BKERR would remain high at the first MOSTRT
shown, going low when De-scrambler lock goes low. Will go high at the next MOSTRT for a good packet.
57
ZARLINK [ ZARLINK SEMICONDUCTOR INC ]
