Epson S1C33210 Personal Computer User Manual


 
II CORE BLOCK: ITC (Interrupt Controller)
B-II-5-20 EPSON S1C33210 FUNCTION PART
DExxx: IDMA enable register
Enable or disable the IDMA request.
When using the set-only method (default)
Write "1": IDMA enabled
Write "0": Not changed
Read: Valid
When using the read/write method
Write "1": IDMA enabled
Write "0": IDMA disabled
Read: Valid
If a bit of this register is set to "1", the IDMA request by the interrupt factor is enabled. If the register bit is set to
"0", the IDMA request is disabled.
After an initial reset, this register is set to "0" (IDMA is disabled).
RSTONLY: Interrupt factor flag reset method selection
(D0) / Flag set/reset method select register (0x4029F)
Select the method for resetting the interrupt factor flag.
Write "1": Reset-only method
Write "0": Read/write method
Read: Valid
With the reset-only method, the interrupt factor flag is reset by writing "1".
The interrupt factor flags for which "0" has been written can neither be set nor reset. Therefore, this method ensures
that only a specific factor flag is reset. However, when using read-modify-write instructions (e.g., bset, bclr, or bnot),
note that an interrupt factor flag that has been set to "1" is reset by writing. This method cannot be used to set any
interrupt factor flag in the software application.
The read/write method is selected by writing "0" to RSTONLY. When this method is selected, interrupt factor flags
can be read and written as for other registers. Therefore, the flag is reset by writing "0" and set by writing "1". In this
case all factor flags for which "0" has been written are reset. Even in a read-modify-write operation, an interrupt
factor can occur between read and write instructions, so be careful when using this method.
After an initial reset, RSTONLY is set to "1" (reset-only method).
IDMAONLY: IDMA request register set method selection
(D1) / Flag set/reset method select register (0x4029F)
Select the method for setting the IDMA request registers.
Write "1": Set-only method
Write "0": Read/write method
Read: Valid
With the set-only method, IDMA request bits are set by writing "1".
The IDMA request bits for which "0" has been written can neither be set nor reset. Therefore, this method ensures
that only a specific IDMA request bit is set. However, when using read-modify-write instructions (e.g., bset, bclr, or
bnot), note that an IDMA request bit that has been set to "1" is not reset by writing.
The read/write method is selected by writing "0" to IDMAONLY. When this method is selected, IDMA request bits
can be read and written as for other registers. Therefore, the IDMA request bit is reset by writing "0" and set by
writing "1". In this case all IDMA request bits for which "0" has been written are reset. Even in a read-modify-write
operation, an IDMA request bit can be reset by the hardware between the read and the write, so be careful when using
this method.
After an initial reset, IDMAONLY is set to "1" (set-only method).