
CYNSE70032
Document #: 38-02042 Rev. *E
Page 103 of 126
15.5
The following explains the SRAM Read operation accomplished through a table of up to 31 devices using the following param-
eters: TLSZ = 10. The diagram of this table is shown in 
Figure 15-5
. The following assumes that SRAM access is being accom-
plished through CYNSE70032 device number 0 and that device number 0 is the selected device. 
Figure 15-6
 and 
Figure 15-7
show the timing diagrams for device number 0 and device number 30, respectively.
 Cycle 1A
: The host ASIC applies the Read instruction to CMD[1:0] using CMDV = 1. The DQ bus supplies the address, with 
DQ[20:19] set to 10, to select the SRAM address. The host ASIC selects the device for which the ID[4:0] matches the DQ[25:21] 
lines. During this cycle, the host ASIC also supplies SADR[21:19] on CMD[8:6].
 Cycle 1B
: The host ASIC continues to apply the Read instruction to CMD[1:0] using CMDV = 1. The DQ bus supplies the 
address, with DQ[20:19] set to 10, to select the SRAM address. 
 Cycle 2
: The host ASIC floats DQ[67:0] to a three-state condition. 
 Cycle 3
: The host ASIC keeps DQ[67:0] in a three-state condition.
 Cycle 4
: The selected device starts to drive DQ[67:0].
 Cycles 5 to 6
: The selected device continues to drive DQ[67:0].
 Cycle 7
: The selected device continues to drive DQ[67:0] and drives an SRAM Read cycle.
 Cycle 8
: The selected device drives ACL from Z to LOW.
 Cycle 9
: The selected device drives ACK to HIGH.
 Cycle 10
: The selected device drives ACK from HIGH to LOW.
At the end of cycle 10, the selected device floats ACL in a three-state condition.
SRAM Read with a Table of up to 31 Devices
 cycle
1
CLK2X
CMDV
CMD[1:0]
DQ
Read
Address
OE_L
WE_L
CE_L
SADR
 cycle
2
 cycle
3
 cycle
4
 cycle
5
 cycle
6
TLSZ = 01, HLAT = 000, LRAM = 1, LDEV = 1.
Figure 15-4. SRAM Read Timing for Device Number 7 in a Block of Eight Devices
PHS_L
CMD[8:2]
A
B
z
0
1
z
z
1
1
SSV
z
SSF
ALE_L
1
z
z
1
z
z
ACK
z
1