XC2700 Datasheet, PDF (22/62 Pages) Infineon Technologies AG – 16/32-Bit Single-Chip Microcontroller

XC2700 Derivatives
XC2000 Family / Alpha Line
Detailed Errata Description
GPT12E_X.001 T5/T6 in Counter Mode with BPS2 = 1X_B
When T5 and/or T6 are configured for counter mode (bit field TxM = 001_B in register
GPT12E_TxCON, x = 5, 6), and bit field BPS2 = 1X_B in register GPT12E_T6CON, then
edge detection for the following count input and control signals does not work correctly:
T5IN, T6IN, T5EUD, T6EUD.
Note: The configuration where T5 counts the overflow/underflow events of T6 is not
affected by this problem.
Workaround
Do not set bit field BPS2 = 1X_B in register GPT12E_T6CON when T5 and/or T6 are
configured for counter mode. Use only settings BPS2 = 0X_B when T5 and/or T6 are
configured for counter mode.
GPT12E_X.002 Effects of GPT Module Microarchitecture
The present GPT module implementation provides some enhanced features (e.g. block
prescalers BPS1, BPS2) while still maintaining timing and functional compatibility with the
original implementation in the C166 Family of microcontrollers.
Both of the GPT1 and GPT2 blocks use a finite state machine to control the actions
within each block. Since multiple interactions are possible between the timers (T2 .. T6)
and register CAPREL, these elements are processed sequentially within each block in
different states. However, all actions are normally completed within one basic clock
cycle.
The GPT2 state machine has 4 states (2 states when BPS2 = 01_B) and processes T6
before T5. The GPT1 state machine has 8 states (4 states when BPS1 = 01_B) and
processes the timers in the order T3 - T2 (all actions except capture) - T4 - T2 (capture).
In the following, two effects of the internal module microarchitecture that may require
special consideration in an application are described in more detail.
1.) Reading T3 by Software with T2/T4 in Reload Mode
When T2 or T4 are used to reload T3 on overflow/underflow, and T3 is read by software
on the fly, the following unexpected values may be read from T3:
• when T3 is counting up, 0000_H or 0001_H may be read from T3 directly after an
overflow, although the reload value in T2/T4 is higher (0001_H may be read in
particular if BPS1 = 01_B and T3I = 000_B),
Errata Sheet
22
V1.7, 2014-10