GMS30C2216 Datasheet, PDF (138/320 Pages) Hynix Semiconductor – 16/32 BIT RISC/DSP

6-22
CHAPTER 6
6.6 Function Control Register FCR
Global register G26 is the write-only function control register FCR. The FCR controls the
polarity and function of the I/O pins IO1..IO3 and the interrupt pins INT1..INT4, the timer
interrupt mask and priority, the bus lock, the CLKOUT pin and the Extended Overflow
exception. All bits of the FCR are set to one on Reset exception (from the RESET# pin or
as a result of a watchdog overrun). They must be initialized according to the hardware
environment and the desired function. The reserved bits must not be changed when the
FCR is updated.
The FCR is preserved on a clock-down reset in order to have the correct interrupt mask and
polarity for the wakeup from clock-down.
Each of the four interrupt pins INT1..INT4 can cause a processor interrupt when the
corresponding interrupt mask bit is cleared. The corresponding polarity bit determines
whether the signal at the interrupt pin must be low (polarity bit = 0) or high (polarity
bit = 1) to cause an interrupt. Additionally, the internal timer interrupt can be enabled or
disabled separately.
Each of the I/O pins IO1..IO3 can be either used as input or interrupt signal (IOxDirection
= 1) or as output (IOxDirection = 0). The CLKOUT pin of the processor can be pro-
grammed to provide a static output level of either high or low, or it can be configured to
provide the processor’s internal clock signal undivided or divided by two or four.
Bits Name
31
INT4Mask
30
INT3Mask
29
INT2Mask
28
INT1Mask
27
INT4Polarity
26
INT3Polarity
25
INT2Polarity
24
INT1Polarity
23
TINTDisable
22
CLKOUTPolarity
21..20 TimerPriority
Description
1 = Interrupt INT4 Disabled
0 = Interrupt INT4 Enabled
1 = Interrupt INT3 Disabled
0 = Interrupt INT3 Enabled
1 = Interrupt INT2 Disabled
0 = Interrupt INT2 Enabled
1 = Interrupt INT1 Disabled
0 = Interrupt INT1 Enabled
1 = Non-Inverted (Interrupt on High Level)
0 = Inverted (Interrupt on Low Level)
1 = Non-Inverted (Interrupt on High Level)
0 = Inverted (Interrupt on Low Level)
1 = Non-Inverted (Interrupt on High Level)
0 = Inverted (Interrupt on Low Level)
1 = Non-Inverted (Interrupt on High Level)
0 = Inverted (Interrupt on Low Level)
1 = Timer Interrupt Disabled
0 = Timer Interrupt Enabled
1 = Inverted / High
0 = Non-Inverted / Low
11 = Priority 6 (higher than Priority of INT1)
10 = Priority 8 (higher than Priority of INT2)
01 = Priority 10 (higher than Priority of INT3)
00 = Priority 12 (higher than Priority of INT4)