SERIES AP440 ACROPACK
USER
’S MANUAL
Acromag, Inc. Tel: 248-295-0310
- 19 - http://www.acromag.com
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www.acromag.com
detected and optionally generate an interrupt.
Memory is organized and addressed in separate banks of eight registers or
ports (eight ports to a bank). The Standard Mode of operation addresses the
first group of 8 registers or ports (ports 0-3 for reading inputs, Ports 4, 5, & 6
which are not used on this model). If the Enhanced Mode is selected, then 3
additional banks of 8 registers are accessed to cover the additional
functionality in this mode (events, interrupts, and debounce). The first bank
of the Enhanced Mode (bank 0) is similar in operation to the Standard Mode.
The second bank (bank 1) provides event sense and interrupt control. The
third bank (bank 2) is used to configure the debounce circuitry to be applied
to input channels in the Enhanced Mode. Two additional mode-independent
registers are provided to enable the interrupt request line and generate a
software reset.
The memory space address map for the AP440 is shown in Table 3.2.
Note that some functions share the same register address. For these items,
the address lines are used along with the read and write signals to determine
the function required.
Standard (Default) Mode
Memory Map
Table 3.2 shows the memory map for the Standard Mode of operation. This
is the Default mode reached after power-up or system reset. Standard
Mode provides simple monitoring of 32 digital input lines without
interrupts. Data is read from or written to one of eight groups (ports) as
designated by the address and read and write signals.
To switch to Enhanced Mode, four unique bytes must be written to port 7,
in consecutive order, without doing any reads or writes to any other port
and with interrupts disabled. The data pattern to be written is 07H, 0DH,
06H, and 12H, and this must be written after reset or power-up.
Enhanced Mode Memory
Map
Table 3.3 shows the memory maps used for the Enhanced Mode of
operation. Enhanced Mode includes the same functionality of Standard
Mode, but allows each input port’s event sense input and debounce logic to
be enabled.
In Enhanced Mode, a memory map is given for each of 3 memory banks.
The first memory bank (bank 0) has the same functionality as the Standard
Mode. Additionally, its port 7 register is used to select which bank to access
(similar to Standard Mode where port 7 was used to select the Enhanced
Mode). Bank 1 provides read/write access to the 32 event sense inputs.
Bank 2 provides access to the registers used to control the debounce
circuitry of these event sense inputs.
