SA-1100 Developer’s Manual 11-65
Peripheral Control Module
11.8.3.7 Suspend/Resume Interrupt Mask (SRM)
The suspend/resume interrupt mask (SRM) bit is used to mask or enable the suspend/resume
interrupt request. When SRM=1, the interrupt is masked, and the SUSIR/RESIR bits in the
status/interrupt register are not allowed to be set. When SRM=0, the interrupt is enabled, and
whenever a suspend or resume condition occurs, the SUSIR or RESIR bit is set. Note that
programming SRM=1 does not affect the current state of SUSIR/RESIR; i t only blocks future zero
to one transitions of SUSIR/RESIR.
11.8.3.8 Reset Interrupt Mask (REM)
The reset interrupt mask (REM) bit is used to mask or enable the reset interrupt request. When
REM=1, the interrupt is masked, and the RSTIR bit in the status/interrupt register is not allowed to
be set. When REM=0, the interrupt is enabled, and whenever the USB host controller issues a reset
to the UDC, the RSTIR bit is set. Note that programming REM=1 does not affect the current state
of RSTIR; it only blocks future zero to one transitions of RSTIR.
The following table shows the location of the UDE, RIM, and TIM bits in UDC control register
(UDCR). The state of RIM and TIM are unknown and must be initialized before enabling the
UDC. The UDE bit is cleared to zero, disabling the UDC following a reset of the SA-1100. This
gives control of the UDC’s pins to the PPC unit that configures them as inputs. Writes to reserved
bits are ignored and reads return zeros.
Address: 0h 8000 0000 UDCCR Read/Write & Read Only
Bit76543210
REM SRM TIM RIM EIM Res. UDA UDD
Reset01000001
Bit Name Description
0 UDD UDD disable.
0 – UDD disabled.
1 – UDD enabled, UDC+ and UDC- used for USB serial transmission/reception.
1 UDA UDC active (read-only).
0 – UDC currently inactive.
1 – UDC currently active.
2— Reserved.
3EIM Endpoint zero interrupt mask.
0 – Endpoint zero interrupt enabled.
1 – Endpoint zero interrupt disabled.
4RIM Receive interrupt mask.
0 – Receive interrupt enabled.
1 – Receive interrupt disabled.
5TIM Transmit interrupt mask.
0 – Transmit interrupt enabled.
1 – Transmit interrupt disabled.
6 SRM Suspend/resume interrupt mask.
0 – Suspend/resume interrupt enabled.
1 – Suspend/resume interrupt disabled.
7 REM Reset interrupt mask.
0 – Reset interrupt enabled.
1 – Reset interrupt disabled.