Type B Macro Service; Asynchronous Serial Reception - NEC PD78212 User Manual

8-bit single-chip microcomputer sub-series
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(3) Example of using the type A macro service
The following example shows how data received through an asynchronous serial interface is transferred to
a buffer area in the internal RAM.
RXB/P30

12.4.6 Type B Macro Service

(1) Operation
The type B macro service transfers data between a data area in the memory specified by the macro service
channel and an SFR.
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 B macro service can be specified for all interrupt requests of the µ PD78214 that can activate a macro
service. For the type B macro service, the SFR pointers can specify any SFRs for data transfer sources and
destinations.
This macro service is a general-purpose version of the type A macro service. It has a data buffer area in a 64K-
byte address space and therefore is suitable for transfer of a large amount of data.
Fig. 12-20 Asynchronous Serial Reception
Internal RAM
0FEC0H
MSC
0FECFH
Mode register
Channel pointer
Receive buffer (RXB)
Shift register
Chapter 12 Interrupt Functions
0F
-1
Type A: SFR → memory
41
CF
Internal bus
INTSR macro service request
12
327

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