ARM Prospector P1100, User Manual, Page: 73 / 154

Hardware Description
ARM DUI 0122A Copyright © ARM Limited 2000. All rights reserved. 3-41
3.12.3 Telecom codec
The telecom codec is a 14-bit sigma-delta codec with programmable sample rates. This
codec has a programmable sample rate, and programmable input and output voltage
levels. It is designed for direct connection to Digital Access Arrangement (DAA).
The telecom sample rate is derived from the SIB clock input to the UCB1200. The
sample rate is programmable in the telecom control register A. The sample rate is given
by the following equation:
The divisor must be greater than 5 and less than 128.
The UCB1200 samples both edges of the clock. The clock signal must have a 50% duty
cycle if an odd divisor is used.
A number of the GPIO pins from the UCB1200 are designated for modem support, as
shown in Table 3-19.
3.12.4 General purpose input/output pin block
The GPIO port provides 10 input/output pins. The pins can be individually configured
as inputs or outputs in the IO port direction and register can be read from or written to
by accessing the IO port data register. Each pin can be programmed to generate an
interrupt on a rising or falling edge.
The pins are assigned as shown in Table 3-19.
F
sa
2 F
sibclk
⋅ ( )
64 telecom_divisor
⋅ ( )
------------------------------------------------------ =
Table 3-19 UCB1200 GPIO pin assignments
Port Signal Function
IO9 UCB_ADSYNC AD converter synchronizing signal
IO8 UCB_DAA_OH DAA off hook signal
IO7 UCB_DAA_RI DAA ring indicator
IO6 UCB_DAA_MUTE DAA mute signal
IO[5:0] UCB_LED[5:0] General purpose input/output. These are connected to
the dual row 10-pin DF13 type connector, JP2.