Table 6-1 . port pin special functions -2, Table 6-1. port pin special functions – Maxim Integrated MAXQ622 User Manual
Page 104
MAXQ612/MAXQ622 User’s Guide
6-2
Maxim Integrated
SECTION 6: GENERAL-PURPOSE I/O MODULE
The MAXQ612/MAXQ622 provide 38 port pins for general-purpose I/O that are grouped into eight port pins on port 0
to port 3 and six port pins on port 4 . Each of these port pins has the following features:
• CMOS output drivers
• Schmitt trigger inputs
• Optional weak pullup to V
DD
when operating in input mode
From a software perspective, each port appears as a group of peripheral registers with unique addresses . Special
function pins can also be used as general-purpose IO pins when the special functions are disabled (ports 2 and 3) .
Table 6-1. Port Pin Special Functions
PORT PIN
DIRECTION
SPECIAL FUNCTION
ENABLED WHEN
P0 .0
Input/Output
IR modulator/envelope output (IRTXM)
IRENV[1:0] = 01b or 10b
P0 .1
Input/Output
Serial USART 0 Receive (RX0)
REN = 1
P0 .2
Input/Output
Serial USART 0 Transmit (TX0)
SBUF0 written
P0 .3
Input/Output
Serial USART 1 Receive (RX1)
REN = 1
P0 .4
Input/Output
Serial USART 1 Transmit (TX1)
SBUF1 written
P0 .5
Input/Output
Timer 0 Input (TBA0)/Timer 1 Input (TBA1)
C/TB = 1 or TBOE = 1
P0 .6
Input/Output
Timer 0 PWM Output (TBB0)
EXENB = 1 or TBCR:TBCS
≠ 00b
P0 .7
Input/Output
Timer 1 PWM Output (TBB1)
EXENB = 1 or TBCR:TBCS
≠ 00b
P1 .0
Input/Output
External Interrupt 0 (INT0)
EX0 = 1
P1 .1
Input/Output
External Interrupt 1 (INT1)
EX1 = 1
P1 .2
Input/Output
External Interrupt 2 (INT2)
EX2 = 1
P1 .3
Input/Output
External Interrupt 3 (INT3)
EX3 = 1
P1 .4
Input/Output
External Interrupt 4 (INT4)
EX4 = 1
P1 .5
Input/Output
External Interrupt 5 (INT5)
EX5 = 1
P1 .6
Input/Output
External Interrupt 6 (INT6)
EX6 = 1
P1 .7
Input/Output
External Interrupt 7 (INT7)
EX7 = 1
P2 .0
Input/Output
SPI 0 Master Out-Slave In (MOSI0)
SPIEN0 = 1
P2 .1
Input/Output
SPI 0 Master In-Slave Out (MISO0)
SPIEN0 = 1
P2 .2
Input/Output
SPI 0 Slave Clock (SCLK0)
SPIEN0 = 1
P2 .3
Input/Output
SPI 0 Slave Select (SSEL0)
SPIEN0 = 1
P2 .4
Input/Output
JTAG interface—TAP Clock (TCK)
(SC .7) TAP =
P2 .5
Input/Output
JTAG interface—TAP Data Input (TDI)
(SC .7) TAP= 1
P2 .6
Input/Output
JTAG interface—TAP Mode Select (TMS)
(SC .7) TAP = 1
P2 .7
Input/Output
JTAG interface—TAP Data Output (TDO)
(SC .7) TAP = 1
P3 .0
Input/Output
External Interrupt 8 (INT8)
EX8 = 1
P3 .1
Input/Output
External Interrupt 9 (INT9)
EX9 = 1
P3 .2
Input/Output
External Interrupt 10 (INT10)
EX10 = 1
P3 .3
Input/Output
External Interrupt 11 (INT11)
EX11 = 1
P3 .4
Input/Output
External Interrupt 12 (INT12)
EX12 = 1
P3 .5
Input/Output
External Interrupt 13 (INT13)
EX13 = 1
P3 .6
Input/Output
External Interrupt 14 (INT14)
EX14 = 1
P3 .7
Input/Output
External Interrupt 15 (INT15)
EX15 = 1
P4 .0
Input/Output
—
—
P4 .1
Input/Output
—
—