ARM Prospector P1100, User Manual, Page: 113 / 154

Programmer’s Reference
ARM DUI 0122A Copyright © ARM Limited 2000. All rights reserved. 4-27
4.5 Programming the UCB1200
The MCP port of SA-1100 is used to provide a communications link with the UCB1200.
This provides a Serial Interface Bus (SIB) compatible with the UCB. Data is transferred
using SIB data frames, which are typically 128 bits long. These are divided into two
64-bit subframes. The UCB reads and writes data using the lower subframe (bits 0 to
63) but ignores the upper subframe (bits 64 to 127).
4.5.1 SIB frame format
The format of subframes used to read and write telecom data, audio data and register
contents are shown in Table 4-19.
Table 4-19 UCB SIB frame format summary
Bit SIBDin definition SIBDout definition
63:48 Control register write data [15:0]
bit 0 = MSB Control register read data [15:0]
bit 0 = MSB
47:32 Telecom input path data [15:0]
bit 0 = MSB
14 MSB bits are read Telecom output path data [15:0]
bit 0 = MSB
bits [15:14] are 0
31 Telecom valid sample flag Telecom valid flag
30 Audio valid sample flag Audio valid flag
29:22 Reserved Always 0s
21 Write bit (write=1) Always 0
20:17 Control register address [3:0]
bit 0 = MSB Control register address [3:0]
bit 0 = MSB
= copy of the address present in
SIBDin
16 Write bit (write=1) Always 0
15:0 Audio input path data [15:0]
bit 0 = MSB
12 MSB bits are read Audio output path data [15:0]
bit 0 = MSB
bits [15:12] are 0