
3–9
information to the TSB12C01A, the phy register-information-receive (PhyRRx) interrupt is set. The register
is at address 24h and is read/write. Its initial value is 0000_0000h. All gap counts (set in the phy device
registers) on all nodes of a 1394 bus must be identical. This can be accomplished by using the phy
configuration packets to set a specific gap count or by using two bus resets, which resets the gap counts
to the default 3Fh. See Section 4.6 for the format of the phy configuration packets.
Table 3–8. Phy-Chip Access Register
BITS
ACRONYM
FUNCTION NAME
DESCRIPTION
0
RdPhy
Read phy-chip
register
When RdPhy is set, the TSB12C01A sends a read register request with
address equal to phyRgAd to the phy interface. This bit is cleared when
the request is sent.
1
WrPhy
Write phy-chip
register
When WrPhy is set, the TSB12C01A sends a write register request
with an address equal to phyRgAd on to the phy interface. This bit is
cleared when the request is sent.
2–3
Reserved
Reserved
Reserved
4–7
PhyRgAd
Phy-chip-register
address
PhyRgAd is the address of the phy-chip register that is to be accessed.
8–15
PhyRgData
Phy-chip-register
data
PhyRgData is the data to be written to the phy-chip register indicated
in PhyRgAd.
16–19
Reserved
Reserved
Reserved
20–23
PhyRxAd
Phy-chip-register-
received address
PhyRxAd is the address of the register from which PhyRxData came.
24–31
PhyRxData
Phy-chip-register-
received data
PhyRxData contains the data from register addressed by PhyRxAd.
3.2.9
The ATF status register allows access to the registers that control or monitor the ATF. The register is at
address 30h. All the FIFO flag bits are read only, and the FIFO control bits are read/write. Its initial value
is 0000_0000h.
Table 3–9. ATF Status Register
Asynchronous Transmit-FIFO (ATF) Status Register
BITS
ACRONYM
FUNCTION NAME
DESCRIPTION
0
Full
ATF full flag
When Full is set, the FIFO is full. Write operations are ignored.
1
AlF
ATF almost-full flag
When AlF is set, the FIFO can accept one more write.
2–3
Reserved
Reserved
Reserved
4
4AV
ATF-4-available flag
When 4AV is set, the FIFO has space available for at least four
quadlets.
5–13
Reserved
Reserved
Reserved
14
AlE
ATF-almost-empty flag
When AlE is set, the FIFO has only one quadlet in it.
15
Empty
ATF-empty flag
When Empty is set, the FIFO is empty.
16–18
Reserved
Reserved
Reserved
19
Clr
ATF-clear control bit
When Clr is set by software/firmware, the FIFO is cleared of all
entries.
20–22
Reserved
Reserved
Reserved
23–31
Size
ATF-size control bits
Size is equal to the ATF size number in quadlets.