Datasheet

Internal Registers
17
SGLS139B − October 2003 − Revised April 2004 TSB12LV32-EP
2.2.9 Phy Access Register at 24h
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 29 30 3128
RDPHY
PHYRGAD PHYRGDATA
PHYRXAD PHYRXDATA
WRPHY
The Phy access register allows access to the registers in the attached 1394 Phy. The most-significant 16 bits
send read and write requests to the Phy registers. The least-significant 16 bits are for the Phy to respond to
a read request sent by the TSB12LV32. The Phy access register also allows the Phy interface to send
information back to the TSB12LV32. When the Phy interface sends new information to the TSB12LV32, the
Phy register-information-receive (PhyRRx) interrupt is set. The power-up reset value of this register equals
0000 0000h. This register, like the cycle timer register, must be accessed as a quadlet. However, the most
significant word can be accessed as a doublet, because the least significant word is unwriteable except in test
mode. This register is not byte accessible.
BIT
NUMBER
BIT NAME FUNCTION DIR DESCRIPTION
0 RDPHY Read Phy
register
R/W When RDPHY is set, the TSB12LV32 sends a read register request with the address
equal to the PHYRGAD field to the Phy interface. This bit is cleared when the request is
sent.
1 WRPHY Write Phy
register
R/W When WRPHY is set, the TSB12LV32 sends a write register request with the address
equal to the PHYRGAD field to the Phy interface. This bit is cleared when the request is
sent.
2−3 RESERVED Reserved
4−7 PHYRGAD Phy-register
transmitted
address
R/W PHYRGAD is the address of the Phy register that is to be accessed.
8−15 PHYRGDATA Phy-register
transmitted
data
R/W PHYRGDATA is the data to be written to the Phy register indicated in PHYRGAD.
16−19 RESERVED Reserved
20−23 PHYRXAD Phy-register
received
address
R/W PHYRXAD is the address of the register from which PHYRXDATA came. For testing,
these bits can be set only when the REGRW bit has been set in the diagnostics CFR at
20h.
24−31 PHYRXDATA Phy-register
received
data
R/W PHYRXDATA contains the data from the register addressed by PHYRXAD. For testing,
these bits can be set only when the REGRW bit has been set in the diagnostics CFR at
20h.
2.2.10 Reserved Registers at 28h−2Ch
These registers are reserved for future use.