UPD784938 Datasheet, PDF (582/733 Pages) NEC – 16-Bit Single-Chip Microcontrollers

CHAPTER 23 INTERRUPT FUNCTIONS
(2) Macro service channel configuration
There are two kinds of type C macro service channel, as shown in Figure 23-30.
The timer macro service pointer (MPT) mainly indicates the data buffer area in the 1-Mbyte memory space to be
transferred or added to the timer/event counter compare register.
The data macro service pointer (MPD) indicates the data buffer area in the 1-Mbyte memory space to be transferred
to the real-time output port.
The modulo register (MR) specifies the number of repeat patterns when ring control is used.
The ring counter (RC) holds the step in the pattern when ring control is used. When initialization is performed, the
same value as in the MR is normally set in this counter.
The macro service counter (MSC) is a 16-bit counter that specifies the number of data transfers.
The low-order 8 bits of the SFR that is the transfer destination is written to the timer SFR pointer (TSFRP) and data
SFR pointer (DSFRP).
The macro service channel that stores these pointers and counters is located in internal RAM space addresses 0FE00H
to 0FEFFH when the LOCATION 0 instruction is executed, or 0FFE00H to 0FFEFFH when the LOCATION 0FH
instruction is executed. The macro service channel is indicated by the channel pointer as shown in Figure 23-30. In
the channel pointer, the low-order 8 bits of the address are written to the macro service counter in the macro service
channel.
Figure 23-30. Type C Macro Service Channel (1/2)
(a) No ring control
High-order addresses
Macro service
channel
Macro service
counter (MSC)
(bits 8 to 15)
(bits 0 to 7)
Timer SFR pointer (TSFRP)
(bits 16 to 23)^Note
Timer macro service
pointer (MPT)
(bits 8 to 15)
(bits 0 to 7)
Data SFR pointer (DSFRP)
(bits 16 to 23)^Note
Data macro service
pointer (MPD)
(bits 8 to 15)
(bits 0 to 7)
TSFR
DSFR
Timer buffer area
Data buffer area
Macro service
control word
Low-order addresses
Channel pointer
Mode register
Macro service buffer address = macro service pointer
Note Bits 20 to 23 must be set to 0.
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Preliminary User’s Manual U13987EJ1V0UM00