This section describes the maximum
operating conditions of the device in Table 7-1. This
section also contains the description of each Operating Performance Point (OPP) for
processor clocks and device core clocks in Table 7-2.
Table 7-1 Speed Grade Maximum
Frequency
DEVICE |
MAXIMUM FREQUENCY (MHz) |
A72SS0 |
R5FSS0 |
MCU_R5FSS0 |
CBASS0 |
DMSC |
LPDDR4(1) |
DRA821xT |
2000 |
1000 |
1000 |
500 |
333 |
1600 (DDR-3200) |
DRA821xL |
1500 |
1000 |
1000 |
500 |
333 |
1600 (DDR-3200) |
DRA821xE |
1000 |
1000 |
1000 |
500 |
333 |
1600 (DDR-3200) |
DRA821xC |
750 |
500 |
1000 |
500 |
333 |
1600 (DDR-3200) |
(1) Maximum DDR Frequency will be limited based on the specific
memory type (vendor) used in a system and by PCB implementation. TI strongly
recommends all designs to follow the TI LPDDR4 EVM PCB layout exactly in every
detail (routing, spacing, vias/backdrill, PCB material, etc.) in order to
achieve the full specified clock frequency. Refer to the
Jacinto 7 DDR Board Design and Layout Guidelines for details.
Table 7-2 Supported OPP vs Max
Frequency see (1)(2)
CLOCK |
MAXIMUM
FREQUENCY(MHz) |
OPP_LOW(4) |
OPP_NOM(3) |
MPU_CLK (A72SS0) |
1000 |
2000 |
MSMC_CLK |
500 |
1000 |
DDRn_CLKP/DDRn_CKN |
1066 (2133 MT/s) or 1333
(2666 MT/s)(5) |
1600 (3200 MT/s) |
(1) OPP and VDD_CPU voltage should be
selected/set at boot time. DVFS is not supported.
(2) Frequency must be limited based
on the lower frequency constraint from this table and
Speed Grade Maximum Frequency. For example, the T speed grade can
operate A72SS/MSMC at 2 GHz/1GHz or 1 GHz/500 MHz. A72SS/MSMC at 2 GHz/1GHz
operation must use OPP_NOM. A72SS/MSMC at 1 GHz/500 MHz operation can use
OPP_NOM or OPP_LOW voltage. Similarly, the E speed grade can operate A72SS/MSMC
at a maximum of 1 GHz/500 MHz. In this case, OPP_NOM or OPP_LOW voltage is
allowed (though OPP_LOW voltage is recommended to reduce power
consumption).
(3) OPP_NOM AVS voltage for VDD_CPU
should be set based on the OPP_1 register setting.
(4) If OPP_0 is not equal to 0,
OPP_LOW AVS voltage for VDD_CPU should be set based on the OPP_0 register
setting. If OPP_0 is equal to 0, OPP_1 register setting should be used.
(5) DDR can be configured for up to
2666 MT/s in OPP_LOW. 2132 MT/s is recommended in OPP_LOW as it more closely
matches the MPU_CLK scaling and also saves power compared to 2666 MT/s.