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Enhanced Modular Input/Output Subsystem (eMIOS200)
PXN20 Microcontroller Reference Manual, Rev. 1
28-34
Freescale Semiconductor
Figure 28-30. Pulse/Edge Counting Single-Shot Mode Example
28.4.1.1.9
Quadrature Decode (QDEC) Mode
Quadrature decode mode uses UC[
n
] operating in QDEC mode and the input programmable filter (IPF)
from UC[
n
– 1]. Note that UC[
n
– 1] can be configured, at the same time, to an operation mode that does
not use I/O pins, such as MC mode (modulus counter). The connection among the UCs is circular, i.e.,
when UC[0] is running in QDEC mode, the input programmable filter from UC[23] is being used.
This mode generates a FLAG every time the internal counter matches A1 register. The internal counter is
automatically selected and is not cleared when entering this mode.
MODE[0] bit selects which type of encoder is used:
count & direction
encoder or
phase_A & phase_B
encoder.
When operating with
count & direction
encoder (MODE[6] cleared), UC[
n
] input pin must be connected
to the
direction
signal and UC[
n
– 1] input pin must be connected to the count signal of the quadrature
encoder. UC[
n
] EDPOL bit selects count direction according to
direction
signal and UC[
n
– 1] EDPOL bit
selects if the internal counter is clocked by the rising or falling edge of the
count
signal.
When operating with
phase_A & phase_B
encoder (MODE[6] set), UC[
n
] input pin must be connected to
the
phase_A
signal and UC[
n
– 1] input pin must be connected to the
phase_B
signal of the quadrature
encoder. EDPOL bit selects the count direction according to the phase difference between
phase_A &
phase_B
signals.
show two Unified Channels configured to quadrature decode mode for
count & direction
encoder and
phase_A & phase_B
encoders, respectively.
amount of events detected
0x000000
EMIOS_CCNTR[n]
Time
B1 Match
Flag Pin/Register
A1 B1 write
Selected Counter Bus
0x000303
0x000090
0x000303
0x000090
A1 Value
1
0x000090
0x000090
B1 Match
A1
Match
amount of events detected
B1 Value
2
0x000303
0x000303
0x000303
A1 Match
0x000090
Notes: 1. EMIOS_CADR[n] = A1
2. EMIOS_CBDR[n] = B1
MODE = 000_1011
A2 Value
3
A2
EMIOS_CCNTR[n]
A2
EMIOS_CCNTR[n]
3. EMIOS_ALTA[n] = A2
Summary of Contents for PXN2020
Page 1: ...PXN20 Microcontroller Reference Manual Devices Supported PXN2020 PXN2120 PXN20RM Rev 1 06 2011...
Page 42: ...PXN20 Microcontroller Reference Manual Rev 1 lxiv Freescale Semiconductor...
Page 64: ...Introduction PXN20 Microcontroller Reference Manual Rev 1 1 22 Freescale Semiconductor...
Page 112: ...Signal Description PXN20 Microcontroller Reference Manual Rev 1 3 44 Freescale Semiconductor...
Page 118: ...Resets PXN20 Microcontroller Reference Manual Rev 1 4 6 Freescale Semiconductor...
Page 372: ...e200z6 Core Z6 PXN20 Microcontroller Reference Manual Rev 1 13 8 Freescale Semiconductor...
Page 412: ...e200z0 Core Z0 PXN20 Microcontroller Reference Manual Rev 1 14 14 Freescale Semiconductor...
Page 821: ...Media Local Bus MLB PXN20 Microcontroller Reference Manual Rev 1 Freescale Semiconductor 27 49...
Page 822: ...Media Local Bus MLB PXN20 Microcontroller Reference Manual Rev 1 27 50 Freescale Semiconductor...
Page 1376: ...Memory Map PXN20 Microcontroller Reference Manual Rev 1 A 118 Freescale Semiconductor...