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518
NAME
SIZE BITS
DESCRIPTION
SIF
1
System clock invalid flag, indicates that the system clock count is invalid.
System Clock Count
23
23-bit time stamp from a 23-bit counter driven by an external 27-MHz clock.
EF
1
Error flag, indicates that there is an error in the transport packet.
System Clock Invalid Flag:
The ceLynx automatically adds the system clock count in the hardware. As a result there should be no time
when the system clock invalid flag (SIF) bit would be 1 indicating an invalid time stamp. This bit is
programmable by software, but hardware does not infer the value of this bit at any time.
System Clock Count:
The system clock count is a 27-MHz clock time stamp. It is 23 bits long and is implemented as a 23-bit
counter running on an external 27-MHz clock. The 27-MHz clock is input on a multiplexed GPIO pin.
Error Flag:
The error flag (EF) indicates that ceLynx has detected an error in the packet. This error indication is an input
into ceLynx in the 130-byte mode. The signal is valid on the first byte of the packet. For each packet, EF
reflects the value of this input signal on the first byte of the packet. This signal is input on a multiplexed GPIO
pin.
5.5.2.1
DirecTV Transmit
For DirecTV transmit, ceLynx can be configured to include any of the 1394 DirecTV headers. The
TXDP(N)CFG.HIM control bit automatically inserts the necessary headers as specified by
DB(N)CFG0.STREAMTYPE.
DirecTV TRANSMIT
PACKET HEADERS
REGISTERS USED TO INSERT
HEADERS
DEFAULT VALUES
FOR DirecTV TX
ISO HEADER
TXDP(N)H0
0008 4010
CIP0
TXDP(N)H1
0009 C400
CIP1
TXDP(N)H2
A000 0000
TIME STAMP
DB(N)CFG0.TSINSERT
—
DirecTV 130_2
TXDP(N)H3
0000 0000
NOTE:
The application must supply quadlet-aligned data in the DirecTV 140-byte transmit
mode. No padding bits are added. ceLynx can automatically add the 10-byte
DirecTV header to DirecTV 130-byte data. ceLynx does not add the 10-byte
DirecTV130-byte header to packets transmitted through the host port. In this case,
the application must supply 140 bytes to ceLynx for transmit.
The host can access the data buffer through registers DB(N)ACC0 and
DB(N)ACC1 for the associated buffer. The host should write all transmit quadlets
except the last to the DB(N)ACC0 register. The host should write the last transmit
quadlet to the DB(N)ACC1 register.
The size of the DirecTV packet is determined by the DirecTV class size. The class size is set in
TXDP(N)CFG.MXC for the associated buffer. The class sizes correspond to the values in Table 517.