Graded Quiz #6 Oct. 13, 2017 Clicker [AB] Covers: Module 2.c through 2.F

Buffer Initialization Code Memory Addr Value org $500 pin fcb $0 pout fcb $0 org $800 pBuff rmb 5 Given the circular buffer described in class, what is this buffer’s current state based on the values in memory? (A) Full (B) Empty (C) Partially full (D) This is an invalid state (E) Not enough information to tell Given the circular buffer described in class, what is this buffer’s current state based on the values in memory? (A) Full (B) Empty (C) Partially full  (D) This is an invalid state (E) Not enough information to tell 500h 02h 501h 00h ‘H’ 800h 801h ‘i’ 802h ‘3’ 803h ‘6’ 804h ‘2’

Buffer Initialization Code Memory Addr Value org $500 pin fcb $0 pout fcb $0 org $800 pBuff rmb 5 Given the circular buffer described in class, what is this buffer’s current state based on the state of memory? (A) Full (B) Empty (C) Partially full (D) This is an invalid state (E) Not enough information to tell Given the circular buffer described in class, what is this buffer’s current state based on the state of memory? (A) Full  (B) Empty (C) Partially full (D) This is an invalid state (E) Not enough information to tell 500h 04h 501h 00h ‘H’ 800h 801h ‘i’ 802h ‘3’ 803h ‘6’ 804h 00h

Buffer Initialization Code Memory Addr Value org $500 pin fcb $0 pout fcb $0 org $800 pBuff rmb 5 Given the circular buffer described in class, what producer/consumer behavior could leave the system in the current memory state? (A) producer put a total of 4 values on buffer, consumer has done nothing. (B) producer put a total of 3 values on buffer, consumer has done nothing. (C) producer has put a total of 8 values on the buffer, consumer has taken a total of 5 off. (D) Either (A) or (B) (E) Either (B) or (C) Given the circular buffer described in class, what producer/consumer behavior could leave the system in the current memory state? (A) producer put a total of 4 values on buffer, consumer has done nothing. (B) producer put a total of 3 values on buffer, consumer has done nothing. (C) producer has put a total of 8 values on the buffer, consumer has taken a total of 5 off. (D) Either (A) or (B) (E) Either (B) or (C)  500h 03h 501h 00h 00h 800h 801h 01h 802h 00h 803h 01h 804h 00h

We need an external flip-flop to latch external interrupts because: (A) You need this for a mask (B) The device acts as our clock (C) The interrupt is edge-sensitive and we must hold the flag value (D) The interrupt is level-sensitive and we must hold the flag value (E) None of the above We need an external flip-flop to latch external interrupts because: (A) You need this for a mask (B) The device acts as our clock (C) The interrupt is edge-sensitive and we must hold the flag value (D) The interrupt is level-sensitive and we must hold the flag value  (E) None of the above

To ignore an externally latched interrupt, the CPU should: (A) Clear the device flag (B) Mask the device flag  (C) Stop clocking the flip-flop (D) Do either (A) or (B) (E) None of the above To ignore an externally latched interrupt, the CPU should: (A) Clear the device flag (B) Mask the device flag (C) Stop clocking the flip-flop (D) Do either (A) or (B) (E) None of the above