73M1822/73M1922 Data Sheet
DS_1x22_017
5.1 Line-Side Device Register Polling
The Register Map as read from a 73M1x22 Host-Side Device consists of two groups. The first is the
Host-Side Device registers (0x00 through 0x11) and the second is a copy of the Line-Side Device registers
(0x12 through 0x1F).
As an extra degree of integrity the 73M1x22 supports the ability to manually monitor the registers of its Line-
Side Device. This is achieved by using the Manual Poll Function. The Line-Side registers that can be polled
are 0x12 through 0x18.
The method is to write the offset address of the Line-Side Device register to be read into the INDX field. The
value of this is the offset from 0x12; that is, Register 0x12 is 0x0, 0x13 is 0x1, etc. The next step is to set
the POLL bit, which causes the device to read the requested register from the Line-Side Device. The value
of the requested Line-Side Device register is written into POLVAL (0x1F). This value is compared with that
of the Host-Side copy and if they are the same then the MATCH bit is set.
The values presented at MATCH and POLVAL are valid approximately 600 μs (depending upon the clock)
after a poll request, and are valid only after the POLL bit has been reset by the Host-Side Device.
Function
Mnemonic Location
Register
Type Description
INDX
0x19[3:0]
0x19[6]
W
Index
Address of the register to be manually polled with the results placed in
POLVAL. This address should be cleared after the poll. Default = 0.
MATCH
R
Polling Match
0 = No match. (Default)
1 = This read-only bit indicates that there is match with the
corresponding polled register in the Host-Side Device. The result of
the polling function can be read only after the POLL bit is reset to zero
by the 73M1x22.
POLL
0x19[7]
W
R
Polling Enable
0 = Polling disabled. (Default)
1 = Manually polls the control register in the Line-Side Device whose
address is given by INDX. The POLL bit remains high until the
MATCH result is available at which time it will be reset to 0 and the
MATCH bit status can be read.
POLVAL
0x1F[7:0]
Polling Value
When 73M1x22 is polled, the content of the Line-Side Device Register
given by the offset address in INDX is placed in this register.
Default = 0. This register can be read after the POLL bit has been
reset to zero, indicating the result is ready.
36
Rev. 1.6
TERIDIAN [ TERIDIAN SEMICONDUCTOR CORPORATION ]
