Epson CMOS 32-Bit Single Chip Microcomputer S1C33L03 Technical Manual page 260

II CORE BLOCK: CLG (Clock Generator)
(8) If the IC enters the debug mode through the connected S5U1C33000H (In-Circuit Debugger for S1C33
Family) when the OSC3 clock is divided by 2, 4, or 8 using the CLKDT[1:0] (D[7:6])/Power control register
(0x40180) to generate the CPU clock (CPU_CLK), the division ratio is automatically changed to 1/1. This
may cause the CPU_CLK frequency to exceed the range assumed. Also it affects the BCU_CLK and BCLK
output clocks as they are generated from CPU_CLK. If the BCU_CLK and BCLK output clock frequencies
exceed the access time condition or operating range of the devices driven with these clocks, debugging
functions such as memory dump as well as program execution may not operate correctly. Therefore, prescribe
remedies for malfunctions when debugging, for example, changing the number of wait cycles and other
parameters in the BCU registers using the debugger, so that the program can be executed and debugged
without problems even when the division ratio changes to 1/1.
(9) When the base clock (CPU operating clock) is generated by dividing the source clock output from OSC3 or
PLL by a value (2, 4, or 8) specified using CLKDT[1:0] (D[7:6])/Power control register (0x40180), the
peripheral circuit clocks must be set lower than the base clock frequency using the prescaler. If the peripheral
circuit clock frequency is equal to or higher than the base clock frequency, the peripheral circuit does not
operate normally.
B-II-6-10
EPSON
S1C33L03 FUNCTION PART