EPI Registers
1145
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
External Peripheral Interface (EPI)
Table 16-22. EPIHB16CFG2 Register Field Descriptions (continued)
Bit
Field
Type
Reset
Description
19
ALEHIGH
R/W
0x1
CS1n ALE Strobe Polarity. This field is used if CSBAUD bit of the
EPIHB16CFG2 register is enabled.
0x0 = The address latch strobe for CS1n accesses is ALEn (active
Low).
0x1 = The address latch strobe for CS1n accesses is ALE (active
High).
18
WRCRE
R/W
0x0
CS1n PSRAM Configuration Register Write Used for the PSRAM
configuration registers (CR).
With WRCRE set, the next transaction by the EPI is a write of the
CR bit field in the EPIHBPSRAM register to the configuration register
(CR) of the PSRAM.
The WRCRE bit self clears once the write-enabled CRE access is
complete.
0x0 = No Action.
0x1 = Start CRE write transaction for CS1n.
17
RDCRE
R/W
0x0
CS1n PSRAM Configuration Register Read Used for the PSRAM
configuration registers (CR).
With the RDCRE set, the next access is a read of the PSRAM's
Configuration Register (CR).
This bit self clears once the CRE access is complete.
The address for the CRE access is located at EPIHBPSRAM
[19:18].
The read data is returned on EPIHBPSRAM
[15:0].
0x0 = No Action.
0x1 = Start CRE read transaction for CS1n.
16
BURST
R/W
0x0
CS1n Burst Mode Burst mode must be used with an ALE which is
configured by programming the CSCFG and CSCFGEXT fields in
the EPIHB16CFG2 register.
Burst mode must be used in ADMUX, which is set by the MODE field
in EPIHB16CFG2.
Burst mode is optimized for word-length accesses.
0x0 = Burst mode is disabled.
0x1 = Burst mode is enabled for CS1n.
15-8
RESERVED
R
0x0
7-6
WRWS
R/W
0x0
CS1n Write Wait States This field adds wait states to the data phase
of CS1n accesses (the address phase is not affected).
The effect is to delay the rising edge of WRn (or the falling edge of
WR).
Each wait state encoding adds 2 EPI clock cycles to the access
time.
The WRWSM bit in the EPIHB16TIME2 register can decrease the
number of wait states by 1 EPI clock cycle for greater granularity.
This field is used if the CSBAUD bit is enabled in the EPIHB16CFG2
register.
This field is used in conjunction with the EPIBAUD register and is not
applicable in BURST mode.
0x0 = Active WRn is 2 EPI clocks
0x1 = Active WRn is 4 EPI clocks.
0x2 = Active WRn is 6 EPI clocks
0x3 = Active WRn is 8 EPI clocks