Type B Macro Service Channel - NEC PD78212 User Manual

(2) Macro service channel configuration
The macro service pointer (MP) indicates a data buffer area in the 64K memory space as a transfer source or
destination.
The SFR pointer (SFRP) is set with the lower 8 bits of the address of an SFR used as a transfer source or
destination.
The macro service counter (MSC) specifies the number of data transfers to be performed.
The macro service channel, which holds the macro service pointer, SFR pointer, and macro service counter,
is located at addresses 0FE00H through 0FEFFH in the internal RAM space.
The channel pointer indicates the macro service channel, as shown in Fig. 12-22. The channel pointer holds
the lower 8-bits of the address.
Caution The following registers cannot be used as SFRs.
IF0L, IF0H, MK0L, MK0H, PR0L, PR0H, ISM0L, ISM0H, and IST
Lower address
↑
↓
Higher address
Fig. 12-22 Type B Macro Service Channel
Macro service counter
(MSC)
SFR pointer
(SFRP)
Macro service pointer,
low (MPL)
Macro service pointer,
high (MPH)
Mode register
Channel pointer
(Macro service buffer address) = (Macro service pointer)
Chapter 12 Interrupt Functions
64K memory space
Buffer area
SFR
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