UPD784938 Datasheet, PDF (576/733 Pages) NEC – 16-Bit Single-Chip Microcontrollers

CHAPTER 23 INTERRUPT FUNCTIONS
(2) Macro service channel configuration
The macro service pointer (MP) indicates the data buffer area in the 1-Mbyte memory space that is the transfer
destination or transfer source.
The low-order 8 bits of the SFR that is the transfer destination or transfer source is written to the SFR pointer (SFRP).
The macro service counter (MSC) is a 16-bit counter that specifies the number of data transfers.
The macro service channel that stores the MP, SFRP and MSC 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 23-26. 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 23-26. Type B Macro Service Channel
High-order addresses
Macro service
channel
Macro service
counter (MSC)
(bits 8 to 15)
(bits 0 to 7)
SFR pointer (SFRP)
Macro service
pointer (MP)
(bits 16 to 23)^Note
(bits 8 to 15)
(bits 0 to 7)
SFR
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