◆SH-2 direct mode

●Block diagram

Figure 3.21 shows the block diagram of SH-2 direct mode. SH-2 allows direct access to peripherals via the two I/O port data registers (PDR1, PDR2) in the SMPC.

Figure 3.21 Block diagram of SH-2 direct mode

●Features

This mode is useful in the following situations:

1. When controlling peripherals that require faster access than can be accessed in SMPC control mode

2. When data output is required for a peripheral

3. When access is required to a peripheral that requires an external latch

4. When you need to access peripherals that are not supported by SMPC

	If none of the above features apply, Do not use "SH-2 Direct Mode" .

Currently (April 1997), the only peripheral that requires the use of SH-2 Direct Mode is the Virtua Gun .

●Settings for using SH-2 direct mode

Figure 3.22 shows an example configuration for using SH-2 direct mode.
Figure 3.22 shows an example configuration for port 1. Note that mode settings can be set independently for each port.

Figure 3.22 SH-2 direct mode setting example

When using SH-2 direct mode and SMPC control mode together (e.g. port 1 = SH-2 direct mode, port 2 = SMPC control mode), the port used in SH-2 direct mode is set to 0 bytes when issuing the INTBACK command. Please use it in mode.