HD6417615 Hitachi Semiconductor, HD6417615 Datasheet - Page 713

• Manufacturer Part Number: HD6417615
• Description: Hardware Manual
• Manufacturer: Hitachi Semiconductor

Status Flag Clearing Timing: After a status flag is read as 1 by the CPU, it is cleared by writing
0 to it. When the DMAC is activated, the flag is cleared automatically. Figure 16.42 shows the
timing for status flag clearing by the CPU, and figure 16.43 shows the timing for status flag
clearing by the DMAC.
(underflow)
TCNT
P
TCNT
input clock
Underflow signal
TCFU flag
TCIU interrupt
P
Address
Write signal
Status flag
Interrupt
request
signal
Figure 16.42 Timing for Status Flag Clearing by CPU
Figure 16.41 TCIU Interrupt Setting Timing
H'0000
TSR write cycle
T1
TSR address
H'FFFF
T2
701