NEC PD78214 - Manual (Page 352)

323
Chapter 12 Interrupt Functions
12
(2) Macro service mode register
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.
Fig. 12-17 Macro Service Mode Register Format
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
(3) Macro service channel pointer
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.
12.4.5 Macro Service Type A
(1) Operation
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.