mc9s12e256 Freescale Semiconductor, Inc, mc9s12e256 Datasheet - Page 154

• Manufacturer Part Number: mc9s12e256
• Description: Hcs12 Microcontrollers 16-bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Chapter 3 Port Integration Module (PIM9E256V1)
3.3.7
Port U is associated with one 4-channel timer (TIM2) and the pulse width modulator (PWM) module. Each
pin is assigned to these modules according to the following priority: TIM2/PWM > general-purpose I/O.
If the timer TIM2 is enabled, the channels configured for output compare are available on port U pins
PU[3:0]. Refer to
the TIM module.
When a PWM channel is enabled, the corresponding pin becomes a PWM output. Refer to
Integration Module (PIM9E256V1)”
If both PWM and TIM2 are enabled simultaneously, the pin functionality is determined by the
configuration of the MODRR bits
During reset, port U pins are configured as high-impedance inputs.
3.3.7.1
Read: Anytime. Write: Anytime.
If the associated data direction bit (DDRUx) is set to 1 (output), a read returns the value of the I/O register
bit. If the associated data direction bit (DDRUx) is set to 0 (input), a read returns the value of the pin.
3.3.7.2
Read: Anytime. Write: Never, writes to this register have no effect.
This register always reads back the status of the associated pins.
154
PWM:
Reset
Reset
TIM2:
W
W
R
R
PTIU7
Port U
PTU7
Port U I/O Register (PTU)
Port U Input Register (PTIU)
0
u
7
7
Chapter 13, “Timer Module (TIM16B4CV1)”
= Reserved or Unimplemented
PTIU6
PTU6
0
u
6
6
Figure 3-43. Port U Input Register (PTIU)
Figure 3-42. Port U I/O Register (PTU)
PTIU5
PTU5
PW15
MC9S12E256 Data Sheet, Rev. 1.08
for information on enabling and disabling the PWM channels.
0
u
5
5
PTIU4
PTU4
PW14
0
u
4
4
u = Unaffected by reset
PTIU3
PTU3
PW13
OC27
3
0
3
u
for information on enabling and disabling
PTIU2
PTU2
PW12
OC26
0
u
2
2
Freescale Semiconductor
PTIU1
PTU1
PW11
OC25
0
u
1
1
Chapter 3, “Port
PTIU0
PTU0
PW10
OC24
0
u
0
0