Renesas SH7781 - Manual (Page 1062)

20. Graphics Data Translation Accelerator (GDTA)
Rev.1.00 Jan. 10, 2008 Page 1032 of 1658
REJ09B0261-0100
20.7.3 Regarding Frequency Changes
During GDTA operation, the CPG register setting must not be used to change frequency. If
frequency is changed during GDTA operation, the GDTA processing is stopped and processing
contents set in CL/MC command FIFO are cleared.
When changing the frequency, the frequency should be changed only after confirming that the
CLSR.EXE bit (bit 3) in CLSR is 0 and the MC_CFA bits (bits 10 to 8) in MCSR are 000.
When resuming the processing, the procedure described in section 20.4.1 (3), CL Processing
Procedure or section 20.4.2 (2), MC Processing Procedure should be used after changing the
frequency. (After a frequency is changed, the processing that was in progress and processing
contents set in the CL/MC command FIFO should be performed again.)