Maxim Integrated MAXQ Family Users Guide: MAXQ2010 Supplement - Manual (Page 42)

MAXQ Family User’s Guide:
MAXQ2010 Supplement
6-4
The port pins on the MAXQ2010 operate the same as standard MAXQ port pins, with input/output states defined in
Table 6-2.
Table 6-2. Port Pin Input/Output States (in Standard Mode)
6.1 GPIO and External Interrupt Register Descriptions
The following peripheral registers are used to control the general-purpose I/O and external interrupt features specific
to the MAXQ2010. Addresses of registers are given as “Mx[yy],” where x is the module number (from 0 to 15 decimal)
and yy is the register index (from 00h to 1Fh hexadecimal). Fields in the bit definition tables are defined as follows:
• Name: Symbolic names of bits or bit fields in this register.
• Reset: The value of each bit in this register following a standard reset. If this field reads “unchanged,” the given bit
is unaffected by standard reset. If this field reads “s,” the given bit does not have a fixed 0 or 1 reset value because
its value is determined by another internal state or external condition.
• POR: If present this field defines the value of each bit in this register following a power-on reset (as opposed to a
standard reset). Some bits are unaffected by standard resets and are set/cleared by POR only.
• Access: Bits can be read-only (r) or read/write (rw). Any special restrictions or conditions that could apply when
reading or writing this bit are detailed in the bit description.
6.1.1 Port 0 Direction Register (PD0, M0[10h])
Each of the bits in this register controls the input/output direction of a port pin (P0.0 to P0.7) as follows:
0 = The port pin is in input mode, either with a weak pullup (if PO = 1) or three-stated (if PO = 0).
1 = The port pin is in output mode, with the output level to drive given by PO.
6.1.2 Port 1 Direction Register (PD1, M0[11h])
Each of the bits in this register controls the input/output direction of a port pin (P1.0 to P1.7) as follows:
0 = The port pin is in input mode, either with a weak pullup (if PO = 1) or three-stated (if PO = 0).
1 = The port pin is in output mode, with the output level to drive given by PO.
PDx.y POx.y PORT PIN MODE PORT PIN (Px.y) STATE
0 0 Input Three-State
0 1 Input Weak pullup high
1 0 Output Strong drive low
1 1 Output Strong drive high
Bit # 7 6 5 4 3 2 1 0
Name PD0
Reset 0 0 0 0 0 0 0 0
Access rw rw rw rw rw rw rw rw
Bit # 7 6 5 4 3 2 1 0
Name PD1
Reset 0 0 0 0 0 0 0 0
Access rw rw rw rw rw rw rw rw