M30218 Datasheet, PDF (111/179 Pages) Mitsubishi Electric Semiconductor – M30218 Group

Serial I/O2
Mitsubishi microcomputers
M30218 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
(3) SBUSY2 output signal
The SBUSY2 output is a signal which requests to stop of transmission/reception to the serial transfer
destination. In the automatic transfer serial I/O mode, regardless of the internal or external synchro-
nous clock, whether the SBUSY2 output is to be output at transfer of each 1-byte data or during transfer
of all data can be selected by the SBUSY2 output • SSTB2 output function select bit (bit 4 of address
034416). In the initial status[ serial I/O initialization bit (bit 4 of address 034216) = “0” ], the status in
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which the SBUSY2 outputs “H” (or the SBUSY2 outputs “L”).
When the internal synchronous clock is selected, in the 8-bit serial I/O mode and the automatic trans-
fer serial I/O mode (SBUSY2 output function: each 1-byte signal is selected), the SBUSY2 output goes to
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“L” (or the SBUSY2 output goes to “H”) before 0.5 cycle of the timing at which the transfer clock goes to
“L” . In the automatic transfer serial I/O mode (the SBUSY2 output function: all transfer data is selected),
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the SBUSY2 output goes to “L” (or the SBUSY2 output goes to “H”) when the first transmit data is written
into the serial I/O2 register (address 034616).
•Serial operation used SBUSY2 output
Operation mode
Transfer clock
SBUSY2 output timing
: 8-bit serial I/O mode
: Internal synchronous clock
: Each 1-byte data
Tc
Internal clock
Serial transfer status flag "1"
(bit 5 at address 034416) _"0"
SCLK2i
(i = 1, 2)(output)
"H"
SBUSY2(output)
"L"
SOUT2
D0 D1 D2 D3 D4 D5 D6 D7
TC : Internal synchronous clock is selected by bits 5 to 7 of address 034816
Figure GA-9. SBUSY2 Output Operation (1)
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When the external synchronous clock is selected, the SBUSY2 output goes to “L” (or the SBUSY2 output
goes to “H”) when transmit data is written into the serial I/O2 register(address 034616), regardless of
the serial I/O transfer mode.
At termination of transmit/receive operation, in the 8-bit serial I/O mode, the SBUSY2 output goes to “H”
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(or the SBUSY2 output returns to “L”), when the serial transfer status flag is set to “0”, regardless of
whether the internal or external synchronous clock is selected. Furthermore, in the automatic transfer
serial I/O mode (SBUSY2 output function: each 1-byte signal is selected), the SBUSY2 output goes to “H”
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(or the SBUSY2 output goes to “L”) each time 1-byte of receive data is written into the automatic trans-
fer RAM.
•Serial operation used SBUSY2 output
Operation mode
Transfer clock
SBUSY2 output timing
: 8-bit serial I/O mode
: External synchronous clock
: Each 1-byte data
Serial transfer status flag ^"1"
(bit 5 at address 034416) "0"
SCLK2i
(i = 1, 2)(Input)
"H"
SBUSY2(output)
"L"
SOUT2
Write to serial I/O register
(Address 034616)
D0 D1 D2 D3 D4 D5 D6 D7
Figure GA-10. SBUSY2 Output Operation (2)
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