MC68HC05X16 Datasheet, PDF (40/232 Pages) Freescale Semiconductor, Inc – High-density complementary metal oxide semiconductor HCMOS) microcontroller unit

Freescale Semiconductor, Inc.
2.3.15 VPP1
2
The VPP1 pin is the output of the charge pump for the EEPROM1 array.
2.3.16 VRH
The VRH pin is the positive reference voltage for the A/D converter.
2.3.17 VRL
The VRL pin is the negative reference voltage for the A/D converter.
2.3.18 PA0 – PA7/PB0 – PB7/PC0 – PC7
These 24 I/O lines comprise ports A, B and C. The state of any pin is software programmable, and
all the pins are configured as inputs during power-on or reset.
Under software control the PC2 pin can output the internal E-clock (see Section 4.2).
Resistive pull downs are provided on port B and/or port C and can be enabled via a mask option
(see Section 1.2). Wired-OR interrupt capability is provided on all pins of port B (see
Section 10.2.3.3).
2.3.19 NWOI
This pin provides another wired-OR interrupt capability in addition to port B. Wired-OR interrupts
are requested when this pin is pulled high (if wired-OR interrupts are enabled), i.e. interrupt
sensitivity on this pin is complementary to sensitivity on the IRQ pin (see Table 10-3 in
Section 10.2.3.1). When this pin is not in use it is recommended that it be tied to V_SS in noisy
conditions. It is not necessary to tie NWOI to V_SS when there is a negligible amount of noise
present.
2.3.20 PD0/AN0–PD7/AN7
This 8-bit input only port (D) shares its pins with the A/D converter. When enabled, the A/D
converter uses pins PD0/AN0 – PD7/AN7 as its analog inputs. On reset, the A/D converter is
disabled which forces the port D pins to be input only port pins (see Section 9.5).
MODES OF OPERATION AND PIN DESCRIPTIONS MC68HC05X16
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