MC9328MX21_06 Datasheet, PDF (13/98 Pages) Freescale Semiconductor, Inc – i.MX family of microprocessors

Signal Descriptions
Table 2. i.MX21 Signal Descriptions (Continued)
Signal Name
Function/Notes
I²C
I2C_CLK
I2C_DATA
I²C Clock
I²C Data
1-Wire
OWIRE
1-Wire input and output signal. This signal is multiplexed with JTAG RTCK.
PWM
PWMO
PWM Output. This signal is multiplexed with PC_SPKOUT of PCMCIA, as well as TOUT2 and TOUT3
of the General Purpose Timer module.
General Purpose Input/Output
PF[16]
Dedicated GPIO. When unused, program this signal as an input with the on-chip pull-up resistor enabled.
Keypad
KP_COL[7:0]
KP_ROW[7:0]
Keypad Column selection signals. KP_COL[7:6] are multiplexed with UART2_CTS and UART2_TXD
respectively. Alternatively, KP_COL6 is also available on the internal factory test signal TEST_WB2. The
Function Multiplexing Control Register in the System Control chapter must be used in conjunction with
programming the GPIO multiplexing (to select the alternate signal multiplexing) to choose which signal
KP_COL6 is available.
Keypad Row selection signals. KP_ROW[7:6] are multiplexed with UART2_RTS and UART2_RXD
signals respectively. Alternatively, KP_ROW7 and KP_ROW6 are available on the internal factory test
signals TEST_WB0 and TEST_WB1 respectively. The Function Multiplexing Control Register in the
System Control chapter must be used in conjunction with programming the GPIO multiplexing (to select
the alternate signal multiplexing) to choose which signals KP_ROW6 and KP_ROW7 are available.
Noisy Supply Pins
NVDD
NVSS
Noisy Supply for the I/O pins. There are six (6) I/O voltages, NVDD1 through NVDD6.
Noisy Ground for the I/O pins
Supply Pins – Analog Modules
VDDA
Supply for analog blocks
QVSS (internally Quiet GND for analog blocks (QVSS and AVSS are synonymous)
connected to AVSS)
Internal Power Supplies
QVDD
QVSS
QVDDX
Power supply pins for silicon internal circuitry
Quiet GND pins for silicon internal circuitry
Power supply pin for the ARM core. Externally connect directly to QVDD
MC9328MX21 Technical Data, Rev. 3.1
Freescale Semiconductor
13