MC9S12HZ256 Datasheet, PDF (148/692 Pages) Freescale Semiconductor, Inc – HCS12 Microcontrollers

Chapter 4 Port Integration Module (PIM9HZ256V2)
4.3.6 Port T
Port T is associated with the 8-channel timer (TIM) and the liquid crystal display (LCD) driver. Each pin
is assigned to these modules according to the following priority:
LCD Driver > timer > general-purpose I/O.
If the corresponding LCD frontplane drivers are enabled (and LCD module is enabled), the FP[27:24]
outputs of the LCD module are available on port T pins PT[3:0].
If the corresponding LCD frontplane drivers are disabled (or LCD module is disabled) and the timer is
enabled, the timer channels configured for output compare are available on port T pins PT[3:0].
Refer to the LCD block description chapter for information on enabling and disabling the LCD and its
frontplane drivers.Refer to the TIM block description chapter for information on enabling and disabling
the TIM module.
During reset, port T pins are configured as inputs with pull down.
4.3.6.1 Port T I/O Register (PTT)
7
R
PTT7
W
6
PTT6
5
PTT5
4
PTT4
3
PTT3
2
PTT2
1
PTT1
0
PTT0
TIM: OC7
OC6
OC5
OC4
OC3
OC2
OC1
OC0
LCD:
1
1
1
1
Reset
0
0
0
0
0
0
0
0
Figure 4-37. Port T I/O Register (PTT)
Read: Anytime. Write: Anytime.
If the associated data direction bit (DDRTx) is set to 1 (output), a read returns the value of the I/O register
bit.
If the associated data direction bit (DDRTx) is set to 0 (input) and the LCD frontplane driver is enabled
(and LCD module is enabled), the associated I/O register bit (PTTx) reads “1”.
If the associated data direction bit (DDRTx) is set to 0 (input) and the LCD frontplane driver is disabled
(or LCD module is disabled), a read returns the value of the pin.
MC9S12HZ256 Data Sheet, Rev. 2.04
148
Freescale Semiconductor