TI380C25 Datasheet, PDF (18/71 Pages) Texas Instruments – TOKEN-RING COMMPROCESSOR

TI380C25
TOKEN-RING COMMPROCESSOR
SPWS012 – JANUARY 1995
adapter-support function (ASF)
The ASF performs support functions not contained in the other blocks. The support functions are:
• The TI380C25 base timer
• Identification, management, and service of internal and external interrupts
• Test-pin mode control, including the unit-in-place mode for board testing
• Illegal state check (checks for illegal states such as parity and illegal opcodes)
clock generator (CG)
The CG performs the generation of all the internal clocks required by the other functional blocks, including the
local memory-bus clocks (MBCLK1, MBCLK2). The CG also generates the reference timer used to sample all
input clocks (SBCLK, OSCIN, RCLK, and PXTALIN). If no transition is detected within the period of the reference
timer on any input clock signal, the CG places the TI380C25 into slow-clock mode. The frequency of the
reference timer is in the range of 10 kHz – 100 kHz.
user-accessible hardware registers and TI380C25 internal pointers
The following tables show how to access internal data via pointers and how to address the registers in the host
interface. The SIFACL register, which directly controls device operation, is described in detail. The
adapter-internal pointers table on the following page is defined only after TI380C25 initialization and until the
OPEN command is issued. These pointers are defined by the TI380C25 software (microcode), and this table
describes the release 2.x of the TI380C25 software.
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