
Agere Systems Inc.
139
Data Sheet
May 2001
and Packet Payload Engine
Ambassador T8110 PCI-Based H.100/H.110 Switch
14
Connection Control—Standard and Virtual Channel
(continued)
5-9627 (F)
Figure 40. PCI Programming
—Read Virtual Channel Static Command
5-9630 (F)
Figure 41. PCI Programming—Read Virtual Channel Scratchpad Command
14.1.2 Microprocessor Interface
When the T8110 microprocessor interface is the selected bus interface, only standard telephony switching is
allowed (no virtual channel switching). A standard telephony connection is made by writing to a location in the con-
nection memory. There is a mode in which the virtual channel memory may be accessed via the microprocessor
interface, included for diagnostic purposes only.
14.1.2.1 Microprocessor Connection Memory Programming
Because the microprocessor interface only allows word or byte accesses, multiple write accesses must occur. The
microprocessor connection memory access mimics the 32-bit PCI access by using a combination of the lower two
address bits [1:0] and holding registers. For byte access, there are a total of three byte-wide holding registers. For
word access, there is one word-wide holding register. The user must load the holding registers with the proper
information first, and then write to the upper byte (or upper word) to actually move data into the connection mem-
ory; refer to Table 110.
31:20
BASE ADDRESS
19:16
0001
15:8
VC IDENTIFIER ADDRESS
7
6:4
000
15:12
0000
1:0
00
RETURNS THE RELATIVE OFFSET
OF DEEPEST BYTE (MAX = 255)
VC PAGE ADDRESS
0 = VC EVEN PAGE
1 = VC ODD PAGE
VCPA
ADDRESS PHASE,
VIRTUAL CHANNEL
MEMORY READ
STATIC COMMAND
DATA PHASE,
VIRTUAL CHANNEL
MEMORY READ
STATIC COMMAND
31:24
00000000
23:18 STATIC
DEPTH (STD)
17:16
11
11:2
STATIC BASE ADDRESS (SBA)
3
0
2:0
000
STATIC/SCRATCHPAD SELECT
0 = STATIC ENTRIES
1 = SCRATCHPAD
SSS
31:20
BASE ADDRESS
19:16
0001
15:8
VC IDENTIFIER ADDRESS
7
6:4
000
15:8 SCRATCHPAD
CURRENT OFFSET (SPCO)
7:0
MEMORY POINTER, CURRENT
OFFSET WITHIN CHANNEL BUFFER.
VC PAGE ADDRESS
0 = VC EVEN PAGE
1 = VC ODD PAGE
VCPA
ADDRESS PHASE,
VIRTUAL CHANNEL
MEMORY READ
SCRATCHPAD
COMMAND
DATA PHASE,
VIRTUAL CHANNEL
MEMORY READ
SCRATCHPAD
COMMAND
00000000
31:24 SCRATCHPAD
CURRENT DEPTH (SPCD)
23:16
00000000
3
1
2:0
000
STATIC/SCRATCHPAD SELECT
0 = STATIC ENTRIES
1 = SCRATCHPAD
SSS
VALUE OF THE COUNTER WHICH
TRACKS THE NUMBER OF BYTES
USED IN THE BUFFER.