27
3819 Group
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
MITSUBISHI MICROCOMPUTERS
Serial I/O Automatic Transfer Data Pointer
(SIODP) 001816
The serial I/O automatic transfer data pointer (address 001816)
consists of 5 bits which indicate addresses in serial I/O automatic
transfer RAM (the value which adds 0F0016 to the serial I/O auto-
matic transfer data pointer is actual address in memory).
Set the value (the number of transfer data-1) to the serial I/O au-
tomatic transfer data pointer for specifying the storage address of
first data.
q Serial I/O Automatic Transfer RAM
The serial I/O automatic transfer RAM is the 32 bytes from ad-
dress 0F0016 to address 0F1F16.
q Setting of Serial I/O Automatic Transfer
Data
When data is stored in the serial I/O automatic transfer RAM,
store the first data at the address set with the serial I/O auto-
matic transfer data pointer so that the last data can be stored
at address 0F0016.
Serial I/O Automatic Transfer Interval Register
(SIOAI) 001C16
The serial I/O automatic transfer interval register (address
001C16) consists of a 5-bit counter that determines the transfer in-
terval Ti during automatic transfer.
When writing the value n to the serial I/O automatic transfer inter-
val register, Ti=(n+2) ! Tc (Tc: the length of one bit of the transfer
clock) occurs. However, note that this transfer interval setting is
valid only when selecting the internal clock as the clock source.
Fig. 17 Bit allocation of serial I/O automatic transfer RAM
Fig. 18 Serial I/O automatic transfer interval timing
Bit
Address
0F0016
0F0116
0F0216
0F1D16
0F1E16
0F1F16
76
5
43210
DO0
DO1
DO2
DO3
DO4
DO5
DO6
DO7
TC
Ti
1-byte data
Transfer clock
Serial I/O output
SOUT
Serial I/O input
SIN
DI0
DI1
DI2
DI3
DI4
DI5
DI6
DI7