10

M67025E

4146J–AERO–06/03

Note:

1. This table denotes a sequence of events for only one of the 8 semaphores on the M67025E.

Figure 1. Semaphore Logic

Table 5. Example Semaphore Procurement Sequence

Function

Status

No Action

1

1

Semaphore free

Left Port Writes ’0’ to Semaphore

0

1

Left Port has semaphore token

Right Port Writes ’0’ to Semaphore

0

1

No change. Right side has no write

access to semaphore

Left Port Writes ’1’ to Semaphore

1

0

Right port obtains semaphore token

Left Port Writes ’0’ to Semaphore

1

0

No change. Left port has no write

access to semaphore

Right Port Writes ’1’ to Semaphore

0

1

Left port obtains semaphore token

Left Port Writes ’1’ to Semaphore

1

1

Semaphore free

Right Port Writes ’0’ to Semaphore

1

0

Right port has semaphore token

Right Port Writes ’1’ to Semaphore

1

1

Semaphore free

Left Port Writes ’0’ to Semaphore

0

1

Left Port has semaphore token

Left Port Writes ’1’ to Semaphore

1

1

Semaphore free