rtd DM6210, Руководство пользователя

Страница: 63 / 91

8-3
The DM6210 has 16 buffered TTL/CMOS digital I/O lines available for digital control applications. These
lines are grouped into four 4-bit ports. Each 4-bit port can be programmed as input or output.
BA + 12: Digital I/O Port 0 (Read/Write 8-bit)
This port transfers the 8-bit Port 0 digital input/output data between the module and external devices. The
bits are programmed as input or output in groups of 4 (P0.0 - P0.3 and P0.4 - P0.7) by writing to the Direction
Register at BA + 15. For all bits set as inputs, a read reads the input values and a write is ignored. For all bits
set as outputs, a read reads the last value sent out on the line and a write writes the current loaded value out to
the line.
Note that when any reset of the computer is performed , all digital lines are reset to inputs and their
corresponding output registers are cleared.
BA + 13: Digital I/O Port 1 (Read/Write 8-bit)
This port transfers the 8-bit Port 1 digital input/output data between the module and external devices. The
bits are programmed as input or output in groups of 4 (P1.0 - P1.3 and P1.4 - P1.7) by writing to the Direction
Register at BA + 15. For all bits set as inputs, a read reads the input values and a write is ignored. For all bits
set as outputs, a read reads the last value sent out on the line and a write writes the current loaded value out to
the line.
Note that when any reset of the computer is performed , all digital lines are reset to inputs and their
corresponding output registers are cleared.
' ' ' ' ' ' ' '
3 3 3 3 3 3 3 3
' ' ' ' ' ' ' '
3 3 3 3 3 3 3 3
BA + 14: Digital I/O Strobe Select (Read/Write 8-bit)
This register is used to select the strobe source for the digital inputs when either Port 0 or Port 1 is
programmed for latch mode. Both Port 0 and Port 1 must use the same strobe signal. Reading this register
returns the current settings.
' ' ' ' ' ' ' '
Port 0 & 1 Latched Input Strobe Select
00 = External Clock 0 (CN3 - 39)
01 = External Clock 1 (CN3 - 43)
10 = External Clock 2 (CN3 - 45)
11 = reserved