NEC PD78P214 Manuale Utente

323

Chapter 12   Interrupt Functions

A macro service mode register is an 8-bit register that specifies the mode of macro service operation.  It is
mapped in internal RAM as part of macro service control word (see Fig 12-16).

Fig. 12-17 shows the format of the macro service mode register.

CHT2

7

CHT1

6

CHT0

5

0

4

MOD3

3

MOD2

2

MOD1

1

MOD0

0

CHT0

CHT1

CHT2

0

1

0

1

0

1

0

1

1

1

Type C

MPT is retained.

MPT is incremented.

MOD0

MOD1

MOD2

MOD3

Type A

Type B

0

0

0

0

Data transfer from memory to SFR

1

0

0

0

Data transfer from SFR to memory

0

0

0

1

1

0

0

1

0

1

0

1

1

1

0

1

0

0

1

1

1

0

1

1

0

1

1

1

1

1

1

1

Without 
ring control

Data transfer
only

With 
automatic 
addition

P0L

P0H

P0L

P0H

With 
ring control

Data transfer
only

With 
automatic 
addition

P0L

P0H

P0L

P0H

A macro service channel pointer specifies the address of a macro service channel.  The macro service channel
can be located in a 256-byte area in the internal RAM at addresses FE00H through FEFFH.  The higher 8 bits
of the address are fixed.  Therefore, the macro service channel pointer specifies the lower 8 bits of the highest
address of the macro service channel.

The type A macro service transfers data between the buffer memory in the macro service channel and the SFR
predetermined for an individual interrupt request.

For this macro service, the direction of data transfer can be specified as either “from memory to SFR” or “from
SFR to memory.”

Data transfer is repeated as many times as previously specified in the macro service counter.  The macro
service transfers 8-bit data.

The type A macro service is suitable for transfer of a limited amount of data at high speed.

The 12 types of interrupt requests listed in Table 12-8 can be specified for the type A macro service.  Table 12-
8 also lists the SFR registers that can be specified as transfer destinations and sources.