SDA6000 Datasheet, PDF (122/380 Pages) Infineon Technologies AG – Teletext Decoder with Embedded 16-bit Controller

SDA 6000
System Control & Configuration
hardware and software reset the watchdog reset completes a running external bus or X-
Bus cycle.
6.1.1 Behavior of I/Os during Reset
During the internal reset sequence all of the M2’s I/O pins are configured as inputs by
clearing the associated direction registers and switching their pin drivers to the high
impedance state. This ensures that the M2 and external devices will not try to drive the
same pin to different levels. Outputs are generally driven to their expected inactive state
during reset. Output pins driven to ‘0’ are: A13 … A0; MEMCLK, CLKEN, XTAL2, COR,
BLANK and TDO. Output pins driven to ‘1’ are: A15 (CAS),A14 (RAS), RD, CSROM,
CSDRAM, WR, P4.5(CS3), P4.4 … P4.0, LDQM and UDQM.
6.1.2 Reset Values for the Controller Core Registers
During the reset sequence the registers of the C166 CBC are preset with a default value.
Most C166 CBC SFRs are cleared to zero, so the interrupt system is off after reset. A
few exceptions to this rule provide a first pre-initialization, which is either fixed or
controlled by input pins.
DPP1:
DPP2:
DPP3:
CP:
STKUN:
STKOV:
SP:
SYSCON:
BUSCON0:
ONES:
0001_H (points to data page 1)
0002_H (points to data page 2)
0003_H (points to data page 3)
FC00_H
FC00_H
FA00_H
FC00_H
0400_H (set according to start-up configuration)
15B7_H (set according to start-up configuration)
FFFF_H (fixed value)
6.1.3 The Internal RAM after Reset
The contents of the internal RAM are not affected by a reset. However, after a power-on
reset, the contents of the internal RAM are undefined. This implies that the GPRs
(R15 … R0) and the PEC source and destination pointers (SRCP7 … SRCP0,
DSTP7 … DSTP0), which are mapped into the internal RAM, are also unchanged after
a warm reset, software reset or watchdog reset, but are undefined after a power-on
reset.
6.2
System Start-up Configuration
Although most of the programmable features of the M2 are either selected during the
initialization routine or repeatedly during program execution, there are some features
Users Manual
6-5
2000-06-15