Datasheet
TSB12LV32 Data Formats
69
SGLS139B − October 2003 − Revised April 2004 TSB12LV32-EP
7 TSB12LV32 Data Formats
The data formats for transmission and reception of data are shown in the following sections. The transmit
format describes the expected organization of data presented to the TSB12LV32 at the data-mover port or
the microcontroller interface. The receive formats describe the data format that the TSB12LV32 presents to
the data-mover port or the microcontroller interface.
7.1 Asynchronous Transmit/Receive (Microcontroller Interface/Data-Mover Port
to/From TSB12LV32)
Asynchronous transmit refers to the use of the asynchronous-transmit FIFO (ATF) interface or data-mover
port to transmit asynchronous data packets. The general-receive FIFO (GRF) and the data-mover port can
recieve asynchronous data packets and/or isochronous data packets. Data is received and transmitted in two
basic formats. The first format is for quadlet packets, and the second format is for block packets. For
transmission, the FIFO address accessed indicates the beginning, middle, and end of a packet. For receipt,
the data length, which is found in the header of the packet, determines the number of bytes in a block packet.
7.1.1 Quadlet Transmit
The quadlet transmit formats are shown in Figure 7−1 and are described in Table 7−1. The first quadlet
contains packet control information. The second and third quadlets contain the 64-bit, quadlet-aligned
address for read and write requests and retry codes for read and write responses. The fourth quadlet is data
used only for write requests and read responses. For read requests and write responses, the quadlet data field
is omitted.
3210 765411109815141312 19181716 20 21 31302928272625242322
prioritytCoderttLabelspd
desination OffsetHigh
destinationID
desination OffsetLow
quadlet data
Quadlet-Transmit Format (Write Request)
Quadlet-Transmit Format (Write Response)
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prioritytCoderttLabelspd
rCodedestinationID
Quadlet-Transmit Format (Read Response)
3210 765411109815141312 19181716 20 21 31302928272625242322
prioritytCoderttLabelspd
desination OffsetHigh
destinationID
desination OffsetLow
Quadlet-Transmit Format (Read Request)
3210 765411109815141312 19181716 20 21 31302928272625242322
prioritytCoderttLabelspd
rCodedestinationID
quadlet data
Figure 7−1. Quadlet Transmit Formats